Once when I was about 5 I had to pee but my dad was in the shower. My mum let me in the bathroom to use the toilet, but warned me not to flush (because that would affect the temp of the shower) That led to me believing that the pipes in the house were connected so that if you flushed the toilet while someone was in the shower, then toilet water would rain down on them!
A childhood belief about bathrooms

others believed things like this
- I used to believe that if I flushed the toilet before I showered, I would take a shower in dirty toilet water.— Chris D
- I used to believe that take a shower meant to go steal a shower from the storeAnon
- I used to think that toilets led to the shower head. That's why I never took a shower :D— scared
- i used to believe rain was when Jesus was having a shower— matt
- I believe that it would rain when God would be having a shower or washing his clothes.— Karina
- I used to believe that if you took a shower after a day of tanning the tan would come off in the shower— Shar