When I was younger, I thought the shower water was pumped from the drain back up into the shower head, so I was afraid that if I peed in the shower, it would come raining back down on me and that grossed me out. Of course, I found it wasn't true, but even still, I won't pee in the shower.
A childhood belief about bathrooms

others believed things like this
- I used to think when I peed in the shower as a kid, the water coming back through the showerhead was my pee.— gregg
- 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 that take a shower meant to go steal a shower from the storeAnon
- I used to think that trolls lived in my shower drain and showered with my dirty water— Troll bather
- I used to believe that if you took a shower after a day of tanning the tan would come off in the shower— Shar
- in this TV show i saw a snake coming up from the drain so everytime i take a shower i go really fast!— scared person