system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What happens in my brain for me to forget huge chunks of a night out when drunk?
gpt
Its not that you're forgetting those huge chunks, its that you are not committing them to memory in the first place.

You can tell someone is blacked out by asking them to remember something like a 7 digit number.  Then ask them to repeat it a few minutes later.  If they're blacked out, then they won't commit it to memory in the first place, and will be unable to repeat it back to you.

You still have all your regular memory though, so you can find your way home or remember old phone numbers, but you will not be putting new memories into place.  So when you wake up, there's really nothing there to remember.