system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are we more sleepy when doing something as opposed to trying to sleep?
gpt
Sleepiness comes in waves. If you went to bed when you were sleepy, you'd be fine. But most people decide to go to bed when they are sleepy. Then they brush their teeth and dick around on their phone for an hour, and the moment is past.