Back when I was little (In preschool), I thought that moms and dads (and all adults) didn't go to sleep. They were awake before me, and stayed up after I fell asleep. so logically, grown-ups must not go to sleep at night!
One time we were playing some make-believe game, and when it was "bed-time" we would pretend to sleep,
except for the dad: "I'm the dad, so I don't sleep"
We all seemed to agree on that without question.
Now that I think about it, that sounds like something someone might say to sound manly:
"Real men don't sleep" :D
A childhood belief about sleeping

others believed things like this
- i used to believe if i went to sleep monsters would get my family, so i thought i stayed up all the time— Luc Lemmel
- I, to this day, believe that when I can't sleep at night it means I'm awake in someone else's dreams... — Turner
- If I pretend to sleep the ghost won't eat me
Anon - I used to only sleep on my back because I thought I would break my ribs if I slept on my stomach.— Molly
- I used to believe that there was an off switch to the ocean so that it could go to sleep at night.Anon
- I used to believe that if you didn't go to sleep, the sun would never come up.— terri