system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: That moment you feel more awake after staying up late for hours.

I'm tired, it's getting late, around midnight. I know I should go to bed, but I press on and continue browsing web pages/ TV channels.
Fast forward it's 2am. I'm physically and mentally exhausted, my eyelids are heavy, I start dozing off, but I force myself to stay awake.
3am. I decide to go to bed. However, I can't fall asleep as easily as I anticipated. Almost as if I missed my window of opportunity to fall asleep. Now I lay awake, unable to rest my eyes. Am I the only one?
gpt
Don't confuse tiredness with sleepiness.

Your body releases sleep hormones in a particular rhythm. The interval is these releases about 1.5 hrs, and the window is about 10 minutes. If you do go to sleep during that time, you'll probably be out almost as soon as your head hits the pillow. The very worst thing to do when you feel this sleepiness is to go "ok, I'll just finish this level/chapter/email and then go to sleep."

Actually, reading in bed is a good way to find that sweet spot. Once you start losing focus and the letters start floating a bit, it's lights out.