system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why am I so tired throughout the day and can easily fall asleep, but the second I'm in bed, I'm wide awake and take hours to fall asleep?
gpt
During the day, demands for your time and attention are omnipresent, sleep is a desirable way to escape them.

Once you're in bed, all the distractions have been silenced and now you have time to think about demands, worries, concerns, etc.