---
title: 'What Exactly IS a Memory?'
source: 'https://youtube.com/watch?v=PqtggjVAi8M'
video_id: 'PqtggjVAi8M'
date: 2026-06-16
duration_sec: 0
---

# What Exactly IS a Memory?

> Source: [What Exactly IS a Memory?](https://youtube.com/watch?v=PqtggjVAi8M)

## Summary

This video explores the biological and neurological basis of memory, explaining how memories are formed, stored, and retrieved in the brain. It emphasizes that memories are not static but are malleable and change each time they are recalled, influencing our identity and perception of the past.

### Key Points

- **Memories as Biological Magic** [0:00] — Memories allow us to experience past moments repeatedly, encoding, storing, and retrieving information about the world and ourselves.
- **Memories Are Not Static** [0:15] — Like dioramas made from wax, memories can melt and change each time they are brought into the spotlight of attention.
- **The Brain's Complexity** [0:45] — The human brain consists of about 86 billion neurons, each connected to up to 10,000 others, forming hundreds of trillions of connections.
- **Neurons Strengthen Connections** [1:48] — When two neurons fire at the same time, their synapses change and their connection gets stronger, forming patterns.
- **Cortical Columns as Processing Units** [2:01] — Neurons organize into columns that process basic sensory information like light, sound, and touch, located in different brain regions.
- **The Assembly: Synchronized Activity** [3:12] — A new pattern of synchronized activity across different brain regions creates the experience of a moment, called the assembly.
- **How Memories Are Formed** [4:07] — The hippocampus creates a blueprint of the winning assembly, saving its configuration and indexing it with related memories.
- **Memory Fragility and Forgetting** [5:36] — Without reinforcement, the assembly fades and synapses weaken, leading to forgetting most moments of life.
- **Ways to Strengthen Memories** [7:18] — Novelty, repetition, and emotions are key mechanisms that strengthen memories by making neurons more changeable and solidifying connections.
- **Remembering Changes Memories** [9:42] — Recalling a memory makes it malleable again; new context and emotions can alter the original memory, so the more you remember, the less accurate it becomes.
- **Therapy and Memory Rewiring** [12:31] — Therapy can help by revisiting hurtful memories in a safe context, literally rewiring the brain to change the narrative of one's life.

### Conclusion

Memories are not perfect recordings but are dynamic and change over time, shaping our identity and decisions. Understanding this can empower us to actively influence our memories and personal growth.

## Transcript

Memories are biological magic that enable you 
to experience bygone moments – over and over.
With them, your mind can encode, store and 
retrieve information about the world and yourself.
But memories are not static like photos.
Like dioramas made from wax, 
each time they’re under the  
spotlight of your attention they 
can melt and change a tiny bit.
Which is a bit concerning because they 
are a huge part of what makes you, you.
They are the personal lore a lot of your  
identity is based on – and the basis 
for your decisions about your future.
What does it mean if they change?
And more fundamentally… What IS a memory? How 
is a moment in time stored in squishy meat?
Your Brain is Weird Madness
The human brain is the most complex thing in the 
universe, so we need to simplify quite a bit.
Scientific models work but are not 
a perfect reflection of reality.
It's a bit like talking 
about elementary particles.
But in a nutshell, what makes you think and feel 
is a complex system of about 86 billion neurons.
Extremely complex electrochemical root 
systems, sending and receiving signals  
through synapses – tiny gaps between cells, where 
an electrical signal is converted into chemicals,  
bridges the distance, is received 
and converted into electricity again.
This is how neurons talk to each other.
And it's a busy conversation because a typical 
neuron is connected with up to 10,000 others.
Together they’re a network of 
hundreds of trillions of connections.
A hundred times more than galaxies 
in the observable universe.
From these connections the 
magic of your existence emerges.
To create purpose in this chaos some 
connections need to grow stronger.
Whenever two neurons fire at the same time their  
synapses change and their 
connection gets stronger.
They become buddies if you want, and 
when their buddy calls they join in.
If we zoom out, patterns emerge.
Dozens or thousands of neurons 
organize into local columns.
These columns are very basic 
information processing units  
that process a tiny piece of all the 
input coming in from your senses:
like dark and light, a location in space, how 
a texture feels, the sound of words and so on.
You have columns for sound, images, touch etc, 
all located in different parts of your brain.
These columns are the gears of the 
biological machine that is your cortex.:
It’s the fundamental hardware you emerge from.
Everything you see, hear, or feel causes the gears  
to move – which means your 
neurons to fire together.
But for you to have a coherent experience,  
these very different gears 
need to be connected together.
Any moment you perceive is 
made from different parts.
As you are watching this video, your eyes 
activate columns for vision and color in  
your visual cortex, your ears transmit 
information to your auditory cortex,  
language areas are decoding my words, while other 
networks keep track of your body and emotions.
All these signals are processed in deeper 
areas of your brain that evaluate them,  
boosting what seems important right 
now and tuning out what doesn’t.
Vastly simplifying, this concert of all 
these different gears connected by levers,  
wheels and screws comes together to create a new 
structure, within your brain machine: The assembly.
A new pattern of synchronized activity 
within the grand architecture of your brain.
This assembly of very different 
neurons firing together,  
is what gives you the experience of 
being a human being in this moment.
So the assembly active in your brain 
right now is you watching this video,  
hearing my voice and learning about memories.
But this is only activity 
without permanent substance,  
like ripples on a pond, nothing will remain.
Without memories you will forever 
be trapped in the present.
To become a being that transcends 
time, you need to etch these fleeting,  
sensory inputs, these temporary moments, 
into something physical that will remain.
And how does your brain decide what becomes 
permanent? With a deadly competition.
How To Store The Past
In reality there is not just one 
assembly active in your brain.
Your brain can’t process everything in the 
outer and inner world with full attention,  
so different assemblies 
are fighting for dominance.
The details are complicated, but at any moment,  
one assembly is winning and deemed 
the most important by your brain.
This is what you are aware of right now.
In your brain, the assembly 
processing the sentence I’m  
speaking to you seems to be 
the most active and wins.
Your brain thinks this matters 
and you are forming a new memory!
Two things are happening right now:  
The neurons of the winning assembly are bathed 
in chemicals that make them more susceptible  
to change and tie them closer together, 
strengthening the synapses between them.
And the memory center and librarian of your 
brain – the hippocampus – is activated.
The details here are super complicated and 
the exact process isn't fully understood yet.
But in a nutshell, your 
hippocampus creates a blueprint,  
saving the rough configuration of the assembly.
The assembly is saved and put 
on an index with all your other  
memories that are associated with 
what was going on in this moment.
Like “everytime I was confused by 
something in a kurzgesagt video”.
Finally you have a memory!
An activation pattern of millions of neurons, 
spanning many different regions of your brain.
Activating any part of the pattern now 
makes the whole assembly fire – now you  
are able to relive a moment of the past 
that is gone forever in the real world.
But this new memory is very 
fragile and still pretty temporary.
Your hippocampus holds its blueprint,  
but without reinforcement, the assembly will 
fade and the synapses will be weakened again.
This is why you forget most moments of your life,  
why you don’t remember how your coffee 
tasted 43 weeks ago on a Monday.
You experience most of your life 
only once, in the moment you live it.
And you don’t just forget what happens to you 
– you also forget what happens in the world.
Most news stories disappear within days,  
and often you never even saw the 
full picture in the first place.
This is why we’ve partnered with Ground News,  
a media literacy tool whose 
mission we fully support.
Their app and website let you compare coverage,  
explore context and see how 
stories spread over time.
You can even see how bias shapes the narrative.
Take this study on Alzheimer’s risk in women.
More than 40 articles were published on it: some 
focus on how menopause shrinks parts of the brain,  
others highlight the benefits of hormone therapy.
You’re actively weighing 
different aspects – and that  
deeper engagement helps your brain to remember.
Most importantly, Ground News reveals "blind 
spots" – stories that only one side is covering,  
showing you what your usual news feed is hiding.
As information bubbles become the norm, thinking 
critically about the news is no longer optional.
And Ground News makes it easier to do just that.
Try it via the QR code on the screen or 
go to ground.news/nutshell.
Our link below gives you 40% off 
an unlimited access subscription,  
and directly supports our channel.
And now, back to your brand-new memory!
For the past to be truly saved, the 
assembly needs to fight for its life.
There are many ways this can happen:
One of them is novelty.
If you walk to the bus, listening to 
some mildly interesting podcast as usual,  
this assembly’s signal is too weak.
This moment in time will be 
lost, like tears in rain.
But if one day you see a crow and 
a squirrel fighting over a nut,  
only for a mouse to steal it – the assembly will 
fire strongly just for the novelty of it all.
Another one is to reactivate the memory 
over and over after it is formed.
Thinking about the animal fight all 
day and telling everyone about the  
strange event will etch it deeper into your brain.
Similar to doing loads of repetition 
when you try to learn something.
And a major way to make a memory 
stick is to feel emotions.
Emotions are really strong mechanisms  
to guide our behavior that evolved 
hundreds of millions of years ago.
They motivate you to avoid danger, 
seek out food and reproduce.
You experience this as 
something feeling good or bad.
Whenever you feel something strongly, your 
ancient brain decides that whatever is going  
on is important for your survival, 
regardless if it's wrong or not.
So many of your strongest memories 
have strong emotional flavors.
The humiliation when you acted 
dumb in front of your crush.
The joy when you beat your dad at Mario Kart.
The devastation when your dog died.
The overwhelming love when 
you held your first kid.
If we just made you feel something, we increased 
the chances that you will remember this video.
Strong activation, repetition and 
emotions do the same thing to your memory:  
We said before that chemicals made the neurons 
able to change – well now they change drastically.
Like wax warming up and melting together, 
the gears of the assembly grow new teeth  
to fit more tightly – neurons grow more 
synapses and fire together even better.
They become closer and more solid.
A lot of this happens while you sleep.
Your hippocampus replays the assembly over and 
over, making it more solid and easier to retrieve  
– which also means that if you don’t sleep 
enough, you literally forget more of your life.
Think about that when you have to study for 
a test next time – without proper sleep,  
you’ll be wasting your time.
But in the end you have a proper long term memory.
A diorama of hardened wax, 
displaying a moment of your life.
A scene etched into a pattern 
of connection inside your brain.
Now you can remember it forever! Well…
Why Remembering Changes Your Memories Forever
To remember you need a cue for the memory, 
something that is part of the original assembly.
A smell, sound, word or maybe 
the image of an angry crow.
Your hippocampus searches its index for the cue,  
hopefully finding the right 
stored assembly, and activates it.
It fires.
Your past experience is retrieved.
The diorama appears in your mind and you 
relive seeing the crow and squirrel fighting!
So far so good.
But as the diorama plays for 
you, you start changing it.
Recalling memories is not like 
loading a video and pressing play.
Under the light of your attention 
parts of the wax become soft again.
Moldable.
Which means that as you experience 
the memory in your mind, the neurons  
involved are bathed in chemicals that make 
them able to change their structure again.
Your hippocampus organizes memories based 
on a few things but most importantly:  
the context of the experience.
And the context is now very different.
When you formed the memory you were tired, in a 
mildly bad mood before work and very surprised.
Right now you are pulling the memory as you 
are having a night out with your friends  
and are telling them your hilarious 
story of the epic squirrel crow fight.
And this new context seeps into the memory.
New connections form, some synapses 
are weakened while others reconfigure.
The diorama changes, becomes 
funnier and more absurd.
Not because you want it to,  
your brain is just incorporating the new 
context of your life into the memory.
As you finish your story, the 
light of your attention moves on,  
the diorama hardens again, now in a new form.
The next time you remember the animal fight,  
you will remember it as way funnier 
than when you actually experienced it.
And it is the same with all your 
memories – when you retrieve them,  
your brain adds new information or forgets some, 
and incorporates your emotions and expectations.
In a sense it updates your past life to 
fit the narrative of your present life.
Over time, even core memories can shift, combine 
with others, or generate entirely new elements.
Your memory system is deeply intertwined with 
the mechanisms for learning – it was never  
designed to create an accurate 
representation of the world.
So your memories are updated as you 
gain new experiences and information.
Ironically, the more you 
remember something actively,  
the less of the original experience remains.
This also means that just because you remember  
something really well it does 
not mean your memory is correct.
It just means that its assembly 
is really strong and vivid.
It’s not a sudden process, your 
identity is safe for today.
It is a slow shift in the overall 
patterns inside your mind.
You are who you are today, but your 
future self will be different and  
they will think and feel differently 
about the things you experience today.
This is also why therapy can be so helpful.
By revisiting hurtful memories in a safe context,  
ideally with helpful introspection, 
you are literally changing your brain.
Literally rewiring yourself 
to get a chance to be happier.
Because yes, your memories may be the lore 
of your life and the basis for your future.
But it turns out, with some help you may be able 
to rewrite your lore and be who you want to be.
And if you want to rewrite the lore of your home,  
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