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.
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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, new human made, original Art Prints just landed in the kurzgesagt shop.
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