I used to beleive that you shouldn't drink too much water before going to bed because if you did, the water level in your body would be too high and would get passed your neck and that would short circuit your brain.
A childhood belief about sleeping

others believed things like this
- I thought tonic water was toxic water and wondered why would anyone drink it if it is toxic?— Dr.Badguy
- My mum used to tell me that you couldn't drink water out of the tap from the bathroom as it was poisonous.Anon
- I used to beleive that when I took a bath w/ my brothers, that if they peed in the water I'd get pregnant.— SabB
- I used to beleive that if you flushed the toilet that it would explode and all the water would shoot out.— Michelle
- When I was young I refused to drink well water because I thought it came out of whales.— itodd
- I used to think that if I ate a fruit seed it would grow in my stomach if I drink water after thatAnon