Let’s do a little exercise. At this very moment, I want you to stop doing anything else you’re trying to do aside from reading this article. Stop checking your phone, close other windows, turn off any music or podcasts you’re listening to and just focus on this. It’s tough to do sometimes, but I promise you it will be worth it.

Ready? OK, now I want you to consider this scenario: all of your memories related to life experiences (known formally as episodic memories) have been wiped away. Your basic skill memories (aka procedural memories) for doing things like eating, speaking English, riding a bicycle and driving a car remain intact. Your entire life story has become a blank slate.

Imagine leaving your house and stepping out into the world. People you knew before losing your memory see you and are puzzled when the light of recognition fails to materialize on your face. Some get angry and storm off, while others seem shocked or saddened. Your phone beeps and boops with emails, text messages and phone calls from complete strangers. Even though you still understand how babies are made, you fail to remember who your parents are or what they look like.

All of your formative experiences have vanished. Every life lesson you’ve learned through school, work, relationships and travel has been erased. Your first kiss, your first slice of pizza, the last conversation you had with your grandfather - gone into the ether. Walking past a school you went to no longer activates thoughts of playgrounds and book reports. A stroll past the building where you got your first job does not generate anything more than a completely neutral emotional state.

Visualize an entire day like this. Take it a step further and imagine that this memory loss is permanent. Do you think you would you try to get back to where you left off, or would your “new” self create a completely different person from scratch? It’s a little bit of a trick question, as you’re making assumptions based on your current personality, which is heavily influenced and shaped by past experiences.

You can decide for yourself which path you think you’d choose, but for the sake of exploration I’m going to assume that the new you chooses the first option. You decide that you’re going to find out who you were, what kinds of relationships you had with the people around you, and how you fit into the world. In short, you’re going to reconstruct yourself.

Do you think this is possible? Before you give an answer, let’s explore how our personalities are affected by the various neural mechanisms involved in memory storage and recall.

Who Are You?

Has anyone ever asked you to tell them your life story? If so, how accurate do you think it was? It’s both impossible and undesirable to include every detail of every day, which means that you need to come up with a sort of summary. You need to piece together disparate pieces of information and come up with a narrative that not only makes sense, but also keeps the listener engaged. If not, then the person who asked you will probably feel like you’ve wasted their time, or their impressions of you might be more negative than you’d like. The natural inclination is therefore to make sure that the storyline you present is more like a movie than reality.

What about the story that you weave in your own head? While it probably strikes you as a no-brainer that people tell each other stories that are less than accurate, you might still be under the impression that you have a clear idea about how you became who you are today. After all, you’re the only one who has experienced your life, and therefore you are naturally the lone authority on what forces have shaped your life. Your brain is always replaying things that have happened to you, and you keep notes on how each event affected you at the time and continues to affect you today.

We all tell ourselves these stories. In many ways, the story you tell yourself is your life’s work. This self-made mental movie gives you clear, unambiguous explanations for the actions you’ve taken in the past and will take in the future. It provides a backdrop for the overarching personality type that you believe you fit into. For some, it’s a David versus Goliath tale, where one lone warrior stands up to the overwhelming odds against them and fights the good fight. Some people weave a classic Greek tragedy where circumstances beyond their control have placed them in unfortunate situations time and time again. Others may see themselves as the itinerant creative artist or daring renegade, living a life that only fellow rebels can ever hope to understand.

This is an entirely natural and understandable tendency. But for the most part, we’re wrong.

Information Filters

Many of us believe that information gets transferred from the external world into our minds in much the same way that computers store data on hard drives.

When a computer stores bits on a hard drive, it’s storing a persistent piece of information that can be reliably fetched in the same condition as long as the hard drive is functional. Everything on a hard drive is stored in 1s and 0s, and our computers use software that can reliably translate those bits into everything we store. It’s a predictable process that yields predictable results. This is the reason that you can open up a file from five years ago and see that it is exactly the same. We depend heavily on the information within our computers remaining static unless we step in to make changes. If this sort of consistency did not exist, using a computer would be a much more frustrating experience.

Imagine how difficult it would be to get anything done if, upon opening a file, it was always a little bit different. You open up a spreadsheet file you created three hours ago and find that several rows of data have gone blank. After opening a picture from a family vacation, you notice that the scenic backdrop has inexplicably changed colors or become blurred beyond recognition. It’s doubtful that you would trust computers as a suitable storage medium for anything you cared about, and would likely go looking for other platforms that might create less distortion.

This latter scenario is actually much closer to how our memories work. Computers use well-understood algorithms and hardware to provide essentially one-to-one storage of information, but our brains aren’t that efficient. The simplest way to think about the realities of your memory is to start viewing your brain as a set of filters, not a blank slate for information storage.

Whenever information comes in from the outside world, it has to go through a series of input filters. First, the external stimuli must be viewed as worthy of storage (what is often referred to as salience). Our brains learn primarily by sensing significant changes in our environments, so if something isn’t interesting enough to us, we’ll forget about it almost immediately. This is a topic I’ve covered before, but if you haven’t read that article, then just understand this: if something we interact with isn’t unusual, our brains generally won’t bother making an effort to store anything about it. This is why you don’t remember every detail of every day of your life: most events in your life are so similar that they get blended together. You do remember very unusual events, like that one time you went bungie jumping in South Africa, while everything else gets generalized into a gelatinous, grey goop with very low information density.

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Assuming that the information in question makes it past this initial filter, it starts to pass through several more filters that end up changing it in a variety of ways. It’s not a predictable process by any means, and factors such as biases, pre-existing knowledge and emotional states can all have a substantial impact on what gets encoded in memory. The end result is a fresh memory that can vary substantially from what you actually experienced.

Recall is basically the same process, just in reverse. Whenever you try to remember something, you’re starting with an inaccurate piece of information because of the aforementioned input filters and then creating even more inaccuracies by putting it through a set of output filters. These filters are somewhat worse than the input versions, because recall involves activating entire networks of memories (a process known as spreading activation). For example, when you think of the word “dog,” a series of memories will pop into your head that are all related to that concept. Rather than just pulling up a picture of a furry, four-legged house pet, your brain automatically activates a variety of related memories. Reading the word “dog” will bring to mind memories of dogs that you’ve interacted with, dogs you’ve seen in films, the sound of barking, milk bones, and a variety of other tidbits that are more or less related to dogs.

Funny dog face

What does this make you think of?

Your recall processes also suffer from many of the same filters as your encoding processes. Emotions, sensory cues and a variety of other factors all manage to find a way to change memories in one way or another. Combined with the effects of spreading activation, you can end up with memories that are complete departures from reality. This happens beyond our own conscious control, and even people who are giving their best effort to tell an honest story can end up telling inaccurate stories purely because they have been deceived by their own flawed memory mechanisms.

The end result of all of this? Your episodic memory ends up being more fiction than reality. Every single time you think about something that’s happened to you, you’re weaving a constantly evolving story. Much like movies that are supposedly “based on a true story”, your brain arbitrarily adds or removes bits and pieces of your memories with each recall. While some people may very well tell conscious lies, it’s worth remembering that many people end up telling untrue stories through no fault of their own - aside from a lack of skepticism towards their own recall abilities, of course.

There are some exceptions to this process, namely incidents that have a clear timeframe and objective evidence. For example, if you lost an arm in a car accident on June 15th, 2008, you can say with an extremely high level of certainty that you lost your arm on that day. Your exact memory of the accident will probably be heavily skewed by the severe emotional impact it had, but you will be living with evidence of its occurrence every day. Even if you lost your memory, you could get a conclusive, objective answer about why you’re missing an arm.

Science also provides us with some pretty good objective information, particularly in fields like physics where verification is the norm. We know that the sun is roughly 93 million miles away because we can objectively measure that. Likewise, we wouldn’t be able to send airplanes into the sky if aerodynamic engineers didn’t have an objective understanding of how air flows over wings. The scientific method is not perfect, but it’s pretty good at highlighting what’s physically going on in the world around us.

Video or photographic evidence can also be helpful. If you were wondering where you were on the 4th of July in 2013 and you find a video of yourself salmon fishing in the Pacific on that day, it’s a pretty solid bet that that’s what you were doing. It is worth noting that photographic and video evidence will be incomplete by its very nature (as it only captures a single perspective and will inevitably miss some details), so it’s not a perfect substitute.

Rebuilding Yourself

Now that you have a better idea about how your memory works, do you still think it’s possible to reconstruct the old you?

Consider how you would go about doing this. The first logical step is to talk to other people, specifically people who have known you for a long time. Parents, grandparents or other relatives (once you figure out who they are) are probably going to be your best bet. They can give you facts to work with, such as where you went to school or got your first job, and, most likely, some stories that highlight your past personality. If you’re lucky, they might even have some photographs or videos that can help you piece things together.

There are several problems with this approach. At the most basic level, other people are incapable of providing entirely accurate accounts of your life. They only observed you from a third-person perspective, and their memories of you are going to be influenced by the factors we explored earlier. A parent would be end up being one of the worst sources of information because they’re likely to have strong emotional biases towards their children - which is bound to severely affect any memories they have of them.

What about experiences that only you can remember? These could be represented by things that happened to you while you were completely alone or in a situation where the only other people were complete strangers. There might also be formative events that occurred with people who are no longer living, such as a deceased relative or significant other. How could you ever hope to get even a fragment of those memories back, and what kind of impact would not having those experiences have on your overall personality? Our best bet here is to conclude that those memories are gone forever, and the impact on you as a person cannot be judged if nobody even knows what happened to you.

Even more troubling is the prospect of bad intentions. If someone knows that you don’t remember anything and you’re trying to reconstruct yourself, how can you trust that they will make an effort to be honest? Perhaps the people you talked to disliked or were jealous of certain qualities that you possessed and now they want to make you “better.” How about if you come across someone who you had serious problems with and they recognized your predicament? It seems doubtful that they would be willing to forget any past transgressions in their present interactions with you.

OK, so other people’s recollections might be somewhat helpful, but likely to be heavily flawed. What about video and photographic evidence of your past self? Unless you had cameras following you around 24/7 for long periods of time beforehand, this is not going to be very helpful. The most you can hope to get out of these is small fragments of your previous mannerisms, beliefs and lifestyle. As mentioned before, you can get a glimpse into specific events this way, but that’s about it.

Sometimes I think about what would happen in the case of someone who writes frequently (such as yours truly). Would it be possible to glean anything worthwhile from reading through your old writing? Maybe, yet I often wonder how much the reconstruction effort would suffer because of the differences between what goes on in a person’s head and the way they express that in external mediums such as the written word. What I write is only a tiny fraction of what I think about, and I don’t think my collected writings come anywhere near summing up who I am as a person. Sure, if you want to get my opinion about certain things in the absence of my direct input, then you could look at my writing and see what you can come up with. Yet even this approach has one gigantic problem: writing is static, and personalities are not.

Your personality, like your memory, shifts with experience. The way someone feels about something today may be dramatically different tomorrow, a month or years from now. Unless that person makes a serious effort to keep their beliefs both public and updated, it’s unlikely that you’ll get the latest version of their thoughts. To take it one step further, this is assuming that this person is being 100% honest about their personally-held beliefs. Our subject may hold controversial beliefs that they’re not interested in letting the world know about, or they may hold some place in the public eye and aren’t willing to compromise that in the name of their beliefs.

If you’re still with me, then you’re probably already catching on to what I’m saying with all of this: that an accurate, total reconstruction would not be possible. If your memory was wiped, that previous person would be functionally dead - no matter how hard you tried to bring them back. You could gather together bits and pieces to create an extremely rough outline of certain aspects of your previous self, but not much else.


Thinking about all of this can be a real mind fuck. For one, it means that your memories about your life are mostly fiction. You have certain memories that possess more clarity than others, but none that are completely free of distortion. It means we can all be fooled by what can feel like an absolutely concrete memory. Even wilder, this all points to a sort of collective delusion that we’re all sort of trapped in.

Taking it further up the chain, you can see how memory distortion plays a key role in many human pursuits. Every time a business person writes a best-seller outlining their blueprint for success, each time a politician invokes the name of a now-deceased predecessor, any time we look back on the past and justify some heinous war - it’s all being driven by incorrect information. Yet we’re all incredibly confident in our ability to comprehend our environments and successfully deduce cause and effect in even the most complex circumstances.

When you die, nobody will have a complete picture of your personality. In fact, it’s a near-certainty that people will fabricate (purposefully or not) information about you for the sake of keeping some story cohesive. Even the people who knew you best will wonder what you would do if you were still there, and incorrectly deduce how you would look at the situation purely because they could never possibly have an objective view of the world around them.

Even more disturbing is that the possibility of losing your memory is very real. You could take a big hit to the head, get Alzheimer’s disease or dementia, or even get an infection that leads to the worst memory loss known to science. Although it’s unlikely, you might end up in the same body, but with a completely different person at the helm.

Part of what inspired this blog post was a conversation I had with a close friend of mine who was visiting Israel at the time (yes, I know, I’m recalling an event from my past - it’s not going to be 100% accurate). We normally have long, detailed conversations about all kinds of topics, and the subject of history came up. I told him about how memory works, how it changes our views without our consent and the impact it has had on history. In particular, the way that people argue about the Israel-Palestine issue struck me as a good example of collective delusion on both sides causing unnecessary suffering. Both parties are constantly invoking long-dead people’s names, ancient religious texts and events from decades (or even centuries) ago. Neither side seems willing to concede any kind of wrong-doing, and both are willing to quickly conjure up rationalizations for their actions throughout the years.

He listened to what I had to say, then asked me an excellent question: “So what are we supposed to do, always say ‘I don’t know’?” It’s a valid thing to ask, and the best I could come up with was “Well, I don’t think saying ‘I don’t know’ all the time is constructive, but it would help if we did it more often.” That’s what I still stand by. I’m not naive even to believe that we can each wander around in our own subjective cloud of confusion and hope to get anything done. We need to step out into the threshold of the world and take action, even in ambiguous or difficult circumstances. But we tend to get ourselves in serious trouble whenever we believe without a shadow of a doubt that we understand everything within our environment and know exactly what the right choices are. The consequences can be especially dramatic when the decisions are being made on behalf of other people.

In short, we might get further as a species if we were willing to acknowledge the limits of our memories and, as an extension, our knowledge of the world around us. It’s not a sure-fire recipe for success, but it’s better than killing each other over perceived transgressions from an uncertain past.


The only solace I can really offer you from all of this is that you’re not alone. We’re all at the mercy of our cognitive systems, and all you can do is try to keep it in check. You can’t possibly hope to succeed 100% of the time. Your biases will always be there, and you can’t escape the way that your memory works - no matter how many “brain hacks” you try out.

The only real tip I can offer you is this: think of your episodic memory in terms of a spectrum, with “That never happened” on one end, and “That absolutely happened” on the other. Consider the middle of this spectrum to be “probably happened, but I don’t remember all the details.” Most of your life is going to fall into this middle category, primarily because of your brain’s tendency to generalize similar experiences. Unless you’re the most special snowflake unicorn in the whole wide world, most days are going to blend together in one way or another.

You should always be willing to move memories up or down the spectrum. When someone tells you about something you did and you come up blank, don’t just assume that it never happened - consider the evidence and move it further towards the other end if appropriate. Likewise, if you tell a story about something you did and other people who were there start questioning your details, think about their input and consider moving it in the opposite direction. This method is not fool-proof, but it works much better than the normal binary system of “Did happen”/“Didn’t happen.”

My personal opinion about the various flaws in episodic memory is that it’s actually pretty liberating. It can be exhausting trying to pretend like you’re the most informed, interesting and intelligent person in the room. I’d prefer to just accept that there are things I don’t know and will probably never know and work on reducing my ignorance in whatever ways possible, with the knowledge that I’ll never completely succeed in my goal. It means there’s always something new to explore, profound discoveries to make and opinions to change. Knowing that I know nothing means that I can always be excited by what the world has to offer me, instead of believing (incorrectly) that I have it all figured out. If you knew everything there was to know, what would motivate you to get up in the morning? That life sounds incredibly boring to me.

Sometimes I get a good laugh when I think about how people might remember me. For example, if someone wanted to hear my voice again after I died, they could just pull up my Anki deck and listen to the bits of sound I recorded for various flashcards. It’s mostly a collection of single words, so I guess maybe someone could build a voice engine out of it and construct whole sentences. Maybe they could even attach it to some kind of AI that pulled the information from my flashcards and deduced what kinds of things I was interested in and how I thought about them.

But then I chuckle and internally acknowledge that this wouldn’t be anywhere near the “real” me. It would just be a weird collection of sounds being strung together on a machine that only had exposure to a very small piece of me. Such a machine would be a sort of “Ace puppet” that existed purely to ward off the existential dread my loved ones were feeling after losing me.

Sadly, once a mind is gone, it’s pretty much gone for good. Appreciate the people around you and the memories you do have right now. If there are any minds that you value in your life, take this opportunity to give them a call, ask them some meaningful questions and listen closely. You’ll never be able to completely capture their essence as a person for use after they’re gone, but at least for that moment, in that tiny sliver of your mutual existences, you’ll both be getting the real deal.

Disclaimer: In an effort to keep this (very long) article somewhat under control, I simplified the neuroscience quite a bit. It’s also worth mentioning that memory, especially long-term memory, is still not 100% understood. Everything I wrote is based on our current understanding of how memory works (and/or the most widely accepted models), but it should not be taken as gospel.