system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: How do memories work? How are they stored in the brain and how do we access them?

It’s crazy to me. I was driving and trying to remember something I heard on the radio earlier this morning, and I could *FEEL* I was close to remembering it. Then I suddenly did remember.
gpt
Your brain is built on a web of neurons. The neurons themselves are connection points that "activate" when excited, broadcasting to the neurons they are connected to. They don't store any information. However, the connections *between* the neurons act as an encoding mechanism. So, imagine you get some input, like you see something. The optic nerves are excited, they are attached to the part of your brain that handles optical input, passing that excited signal along in different ways (sort of like a game of Plinko). Different neurons require different amounts of incoming "excitement" to activate themselves. They then cascade that activation through the brain in different ways depending on the type of input they got.

Imagine a spiderweb. Let's say you see a bicycle. A certain pattern of strands in the web "vibrate", but not all of them. Every time you see a bicycle that same pattern vibrates in the web. That pattern is the concept of a bicycle as it pertains to visual input. Let's say you see a motorcycle, you might activate ALMOST the same pattern, with a few strands being different. That's because the more similar the pattern, the more similar the ideas. If you saw, say, a banana, it might activate a COMPLETELY different pattern. This is how your brain conceptualizes everything (neural activation patterns). It works like an encoding in a lot of ways. That pattern is your brain's own personal encoding for "bicycle". Another brain would associate that pattern with something, potentially, completely different (but in actuality would probably not be able to make sense of it at all, since that brain wouldn't have the same neural connections).

As you learn things, experience things etc, new connections in the web are made to accommodate new encodings. As you forget things, old connections are dissolved/degraded (because they aren't being used as often) also to make room for new encodings. Not every brain is equal in this process, but every brain works this way. Some are more efficient at it others not as much.

This is a contrived example. But it gives the gist of how the brain stores and recalls information. It's not like a computer's hard drive at all. It's a completely different mechanism.