My best friend and I used to believe that there was a little green man who lived inside the toilet and would eat your poop! My fear of him was so great that I would sit backwards on the toilet so I could watch and make sure he wasn't there. I stopped that when I was maybe 10. I still retain a fear of the loud flushing sound a toilet makes- I make sure flushing is the last thing I do before I leave the bathroom... though I don't generally admit it.
A childhood belief about bathrooms

others believed things like this
- I used to believe the sound of a flushing toilet was nearly identical to the 90210 theme. — Laurenne
- My best friend used to believe that when it rain and thundered that God was flushing his toilet. — Jelly Bean
- 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 think if you didnt get up before flushing the toilet would eat you...Anon
- i used to think when it started raining it was god flushing the toilet— edel
- I was certain that rain was created by God having a pee and flushing his huge toilet above us— Emma H