system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do we sometimes forget instantly what we were thinking of? A second the thought is there, next second, due to very minor distraction, it is completely gone?

For example, going to the fridge to bring something, open the fridge and stare blankly at it, having no idea what we were going to take.
gpt
I was told by a well learned friend that explained it to me like this. The short term memory we have is similar to RAM, where you don't have that much space for stuff, so your brain needs to dump it often. It won't randomly dump stuff though, it'll wait until a different environment or change in the train of thought, like passing through a doorway.