My grandmother allowed me to watch Stephen King's "IT" at an obscenely young age. For years afterward, I thought that if I flushed the toilet, a demonic clown would come out of the toilet and kill me. :-)
A childhood belief about films

others believed things like this
- I used to believe that Limabeans would kill you if you didn't eat them.
I flushed them down the toilet.— Lima - I used to believe that monsters lived in my toilet and they ate my poop and urine when i flushed the toilet.Anon
- 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 think if I left the toilet seat open my cat would get flushed down the toilet.— G
- I used to believe that the toilet would suck me down if I flushed it.— :-)
- i use to believe that if i flushed the toilet when i was still on it would suck me down to who knows whereAnon