June 11

Memories Are Unreliable: Why We May Be So Sure Yet So Wrong At the Same Time

Have you insisted that you left the keys on the table only to find them later in your coat pocket? Or, had trouble recalling the name of the movie but can quote dialogue from the movie verbatim? Or, argue with your spouse about stuff you heard on the radio last week while you both swear your versions are right? Misremembered incidents are many, but the point they drive home is one. At best, our memories are unreliable. This.

Memory lapses such as those described above can be disconcerting. You may start to lose credibility with others or even with yourself. My family refers to this as the "so wrong but so sure of herself" syndrome. And, if you're like me, you may or may not have typed "symptoms of early-onset dementia" in your google search bar.

But rest assured. Worrying about early-onset dementia for many of us is like worrying about dying from a plane crash. Yes, it is possible to be killed in a plane crash. But the odds are low. So low that as of 2019, the National Safety Council couldn't estimate the odds of dying in a plane crash because there were too few fatal crashes compared to someone dying of heart disease (1 in 6) or cancer (1 in 7.)

So, if it is not due to rapid deterioration, why are our memories so unreliable? The short answer—it's because we cannot and don't need to remember everything. In tech-speak: too much low-quality data, not enough storage.

Phantom Flashbulb study

The day after the Challenger space shuttle exploded, 106 students in an Intro Psych class were asked to fill out a questionnaire describing their circumstances—where they were and how they reacted—when they found about the incident. Two and a half years later, the same students were given the same questionnaires and asked to recollect, from their memories, the circumstances of the same incident.

This study is popularly referred to as the phantom flashbulb memory study. A flashbulb memory is a highly vivid and detailed snapshot of the moments and circumstances of unusual and highly emotional moments in our lives. Examples of such moments include where we were on 9/11 when the planes hit the twin towers, the memory of a child's birth, or winning the Oscar.

Psychologists Ulric Neisser and Nicole Harsch, who conducted the study, noticed substantial discrepancies in the subjects' recall of their circumstances between the two studies. Over 40% of the subjects significantly misremembered the incident over time.

The study's conclusion: our memories are unreliable, especially as time goes on.

To find out why let's take a deeper dive into some key characteristics of memories.

Memory is limited

What did you eat for lunch last Wednesday?

Where did you park when you went to the grocery store a few days ago?

Unless last Wednesday was a special day in your life, or you did something out of the ordinary, you won't remember what you ate for lunch. Similarly, you are likely not to remember where you parked at the grocery store unless there was something unusual about the parking spot or the vehicles parked around you.

Our lives are mostly routine and made up of a series of mundane tasks, one after another. And that's not a bad thing. Routines are comfortable. Someone dealing with a life-threatening sickness wouldn't hesitate an instant to trade places with you just to get a break. Normal isn't boring.

But, not so for our memories.

Routine is recorded in invisible ink

Our memories do not care about routine. That's because there is no lesson to be learned from predictable, everyday occurrences.

On the other hand, out-of-the-ordinary events get us emotionally excited. We want to recollect how it felt when we fell in love for the first time or received the first large paycheck, or won employee of the year at the annual company conference. These experiences are what we like to reminisce about time and time again. They trigger dopamine hits and make us feel better about ourselves and the world in general.

We don't just remember positive experiences. We also tend to play back out-of-ordinary negative experiences in a loop. Bad memories act as warning triggers and help us avoid exposure to potentially unpleasant situations in the future. So, our survival mechanism will keep reminding us of the lessons we learned.

The everyday rigamarole of existence, though? Irrelevant.

Imagine two files in your brain.

  • File X: The first records everything you do— from the time you wake up until you go to bed—in invisible, evaporating ink. It's hard to retrieve because it's written invisible ink, and over time it simply disappears because it's in evaporating ink.
  • File Y: The second is an organized, indexed file and has just a few notable entries—those unique out-of-the-ordinary experiences (both positive and negative.) This file is frequently used, maintained, and updated, as we'll see further below.

About 95% of our lives are in File X. It's the 5% that we hold on to and worry about.

Takeaway: If you want to remember something long-term, find a way to make it unique.

Memory is subjective

No two people in the world look at the same object and perceive the same thing. We may agree on the broad outline. But that's about all we'll agree on.

For instance, let's say you, and I take a walk together and stop in front of a tree. We can both agree that we're indeed looking at a tree. We may even agree on the tree species; Sycamore tree (Platanas racemosa.) But soon, we'll start to differ on the details. I may see the trunk a Bison brown color while you may insist it's a Nomadic brown.

Many factors will influence your perception of the tree compared to mine. What else was in your line of vision? How much ambient light hit your retina vs. mine? What else was vying for your attention in addition to the tree (physical or mental)?

It's easy to agree on "objective truths" at a higher level (that we were both looking at a tree), but when we start to get into minutiae (the color of the trunk or leaves, the apparent health of the tree, etc.), we may be worlds apart.

That's bad enough in real-time. Now, add to the above the added tax of storing and retrieving this information as a memory. Trying to sync the two memories would be like playing Pictionary with someone who draws poorly and tries to get you to guess the word "Hyena." Fat chance.

So, even if two people witness the same event, their recall (over time) is likely to be wildly different and subjective. And they may both be right, in their own ways.

To understand why we need to understand the basics of how memories are formed.

Memory formation 101

At a very high level, here's the science on memory formation.

When you have a sensory input (see something, hear something, feel something), you store that information in real-time in your prefrontal cortex (PFC). This is your working memory. It's a minuscule sliver of what you're exposed to.

The scientific consensus is that only about 3 to 7 items can be stored in the PFC. And this storage only lasts for about 10-15 seconds. That's it. After that, it's gone. Poof. Replaced with the next. For instance, your working memory has forgotten what was in the above paragraph. Which is why now you have gone back to re-read what was there.

If you deem some information to be necessary, unusual, or relevant, your brain indicates it with a marker. That piece of data is then transported from the working memory into more persistent storage. Eventually, a small subset of really important (to you) data makes it to long-term storage in the hippocampus.  

All the while, the memory is fragile. So any interruption, contradiction, confabulation, stress will directly impact the memory while it makes its way to long-term storage. If ever there was a glitch process, it's this one.

Memory storyboard

Let's continue with the example of the sycamore tree.

What you see is not what you remember. Not even close. That's because we use multiple sense organs to construct a persistent memory.

We don't just see the tree, but we smell the bark, hear the wind blowing, and feel the leaves rustling under our feet. And these sensory perceptions constantly change. By creating a memory for the tree, we've already edited what we originally saw by adding or subtracting details.

True short-term memories are typically like snapshots in time. If your brain deems a memory is worth preserving, the details are transferred over from the PFC and consolidated in the hippocampus for longer-term storage. In that process, though, the memory is integrated and weaved together with what you already have.

In essence, we go from having a few scattered random frames of photographs to an Oscar-worthy video with sound effects, background score, and special effects. 

No wonder our memories are unreliable. Is there a way to get more accurate with the capture then?

Attempting to freeze

I once had this bright idea that I'd record, in detail, and as soon as possible, any precious memories on paper so I don't have to rely on my brain to remember, i.e., create my own backup tool. Guess what?

I soon realized the limitation of language. When I try to record a multi-dimensional, multi-sensory experience into a two-dimensional essay on paper, my limited vocabulary is insufficient to recreate the original experience.

We can wax eloquently on paper, but it's no match to the rich sensory orchestra playing within each one of us.

So far, we've seen how the memory formation process is in itself fraught with many risks. But wait. There's more. It gets even more bizarre with the recall.

Memory recall

Every time we retrieve our memory, it's like opening up a Google doc in edit mode with Autosave turned on. Right away, the version you are editing is different from the original. By the time you put it back, you replace the original one with a newer version.

Since multiple sense organs are involved in constructing the original memory, we struggle to replicate the sensation during recall. This creates holes. Since we are humans and don't like gaps in our stories, we don't hesitate to add more drama or flair to a memory before putting it back in the closet. And this happens each time the memory is retrieved.

If you wonder how memories grow legs, this is why.

Accuracy and memory are not best friends, so we shouldn't be surprised that our memories are unreliable.

This brings me to concocted memories.

False Memories

If you were in the trenches in World War II, for instance, your memories of the war can change your perspective in life quite dramatically compared to someone who may have simply heard of the war.

But this is where we can witness how remarkable human ingeniousness really is. Through our empathy or repeated exposure to some stories, we sometimes have "memories" of events that we weren't even part of. I call this the like I was there condition.

You remember how you were the class clown or how you stood up to the bully in your pre-school when you were just three years old.

Now, let me ask you this? Do you really, honestly remember? In all likelihood, you simply heard these stories from your parents (repeatedly) as you were growing up. At some stage, your brain coopted these learned instances as memories. At that stage, you start to truly believe these were events you experienced rather than ones you had simply heard about it.

The more you believe in it as a memory, the stronger it is stored as one. The line between fact and fiction blurs. Isn't that enough to tell us that our own memories are unreliable?

Another variant of memory lapse we all experience is that of selective amnesia. And yes, it's more than just conveniently forgetting to take out the laundry or loading the dishwasher.

Selective amnesia

I've run more than a few marathons to know the pattern of what it feels like each time. Here's the general timeline.

  • Mile 1 – What a great crowd and so much energy. Wow!
  • Mile 8 – This is easy; I could keep going
  • Mile 15 – Should have gone to the finish with the half-marathoners; those lucky dogs.
  • Mile 22 – Never again in my life will I ever do this. Never!
  • Mile 26.2 – Yay! Such an accomplishment.
  • A few days later - Sign me up for the next one!

So, what happens between mile 22 and "a few days later"?

Selective amnesia.

A few days later is when I go back and retrospectively edit my pain scale for mile 22. Yes, it was painful. But the sheer accomplishment of getting to the finish line on two feet, still upright, is usually enough to make me want to do this again. And again.

Memory is a physiological phenomenon, and so it isn't that I purely wish the pain away. The cytokines during intense exercise also interfere and distort the memory of the event.

Same with childbirth. Positive experiences tend to have positive memories. Knowing how painful childbirth is, why would people keep having children?

We need to thank evolution for this. This selective amnesia keeps us moving forward as a species. There is a beauty in forgetting that we tend not to appreciate as much as we should.

Feeling discouraged? Yes, we've established memories are unreliable. But there are things we can do to be less scatterbrained.

Tips to remember better

Here are six tips to best preserve our fond memories and also help create and sustain new ones.

1. Pay attention

No attention = no memory.

If you want to remember something, the least you can do is pay focused attention. It would be easier to recall whether you locked your door if you lock the door consciously. Paying attention creates that first snapshot in your PFC.

A scattered brain creates a fragmented memory. We've seen how fraught with risks the memory creation process already is. Multitasking makes it much worse.

And how do we learn to be attentive? By learning to slow down and stay present. No prizes for guessing which rabbit hole that takes us into – Meditation. Do it. Already.

2. Add drama

Pure semantic facts are about as interesting as standing in line at the post office and letting people skip you.  For you to remember something, you need to make it interesting to you.

Adding emotion—positive or negative, preferably the former—will help with memory retention. We like human interest stories rather than neutral facts.

3. Rehash

Time is the biggest enemy of memory. An unopened memory is a lost memory.

Use it or lose it is a philosophy that is very relevant to memory retention.

Sometimes if you wonder why you remember insignificant bits of information, it's likely because you rehashed it by retrieving the memory often. Each time you retrieve a memory from the closet, you strengthen the index for retrieval. You make it easier to pinpoint that memory amidst the vast recesses of your brain.

Suppose you want to remember a loved one who recently passed away or an incident you witnessed that you may be called to testify to later; it's best to retrieve the memory of the person or incident often. To cement the memory in your long-term storage.

Here is the critical part– the converse is true too. If you have a traumatic or bad memory and would like to forget it, don't keep talking about it at the drop of a hat. For instance, if you felt someone wronged you, simply rehashing that material multiple times will strengthen the memory and prevent you from moving on.

4. Concoct stories and visualize

Mnemonic champions perform incredible memory feats by using clever visualization techniques and concocting bizarre stories about neutral facts. If you're keen to impress people in a room by reciting the first hundred digits of pi, I recommend you watch videos by memory champion Joshua Foer to get some tips.

Again, the basis of this technique is that we remember meaningful and emotionally heightened events rather than neutral facts. The only way to make many random numbers interesting is by creating a farfetched story about those numbers.

5. Sleep

Don't shortchange sleep. Sleep is the single most important physiological process that aids in better memory. Synaptic pruning of unwanted neural connections occurs during sleep. Glial cells clean up and prevent dementia and plaque accumulation.

The least we can do is to sleep to let our body perform its essential maintenance functions.

6. Learn something new

Read this post for how you can rewire and regenerate new neural cells. Aging will inevitably do its thing, but by learning something new, we can counteract aging.

Even in young brains (not yet bogged by aging worries), information is retained when there is spacing between learning. Cramming is useless. All you do with cramming is take and lose information at pretty much the same rate.

But if you follow good learning techniques and incorporate spacing between learning, you have a better chance of longer-term retention. Another method to use is Interleaving, i.e., mixing up learning different subjects instead of sticking to one area at a time.


It may be the understatement of the decade to say our memories are unreliable. But that is what makes us human. The alternative would be that we'd remember every grievance, every sad story that ever happened to us. More importantly, it helps us change our focus from looking back to staying present.

Memory and imagination are not that different after all. If our willingness to romanticize the past and reminisce nostalgically gets us through the day and doesn't harm anyone, I say, why not? We may not be accurate, but at least we can be happy, right?


I would like you to ponder a couple of questions:

1. Why not cut someone slack when they think they are right but you know you're wrong? And vice-versa.

2. Memories are unreliable. So, why not simply stop stressing about remembering and instead enjoy the present moment to its fullest extent? View the glory of the sunset through our own eyes instead of always trying to make the moment Insta-worthy.



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