When i was around 9 or so my dad told me that if you sleep on your back with your knees bent upward towards the ceiling, little goblins would sit on your knees and make scary faces, causing you to have nightmares. (apparently a South American myth to scare kids. I dont know) But to this day, i'm 25 years old now, if i find myself even laying with my knees bent i still get a little paranoid about those little goblins getting ready to scare me.
A childhood belief about sleeping

others believed things like this
- I used to believe that kidneys were located in your knees.Anon
- when i was younger i thought ac/dc's dirty deeds (done dirt cheap), was dirty knees and the thunder cheeks.— S
- When I was a little kid, I used that think that cars bent when they turned.Anon
- When I was younger, about seven, I used to think that cars bent when they turned! :)— Brittany Serell
- My mom used to tell me that if I sucked my thumb, my teeth would get so bent up, they would all fall out— I dont suck my thumb anymore
- I used to believe that tornadoes were spinning jack-o-lanterns in the air bent on destroying my house.Anon