I watched Alfred Hitchcock episodes the old black and white ones when I was young about 6 or 7. I watched one where he talked about water torture where a person was strapped in a chair and water was let drip on his head until a hole ws eroded in the persons head. I used to think that standing under a running shower would erode my body and I would check for dents after every shower
A childhood belief about bathrooms

others believed things like this
- I used to think that toilets led to the shower head. That's why I never took a shower :D— scared
- I used to think that if you go into a shower nothing can hurt you because you're protected by water — Foxxip
- 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 trolls lived in my shower drain and showered with my dirty water— Troll bather
- 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