system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why do we forget nouns like names of people and places, which we know. And this happens just the exact second when we need that name from the brain.
gpt
* Your memories are not like computer files they are more like a series of "clues": your five senses and emotions factor into memories
* A theory about sleep and dreams is that (among other things) it's memory consolidation. Your brain organizes memories while you sleep - one correlation is that people who learn new things in a classroom or formal training report lots of dreams when they sleep.
* Some memories fade or become disjointed because they are not used. That person from your teen years that interacted with -a lot - is now "the dude with the shirt" because the memories weren't used, or weren't used that much.
* You can recover some of that, so when the "the dude with the shirt" send you a FB request, your brain will try to get as much as it can - but will fill in the blanks with new information.
* Your brain can store lots of information - it's the recall and access where the problems occur.  If it's not used, the "links" decay as memories that are used take priority.

So a name of a person you don't interact with that much, a place name you haven't used, that word you need - your brain has prioritized the recall of other, more used memories. And now you're caught short.