I used to believe that their was a gorilla that lived outside my window. I couldn't sleep facing the window because he would bite my face off, and I couldn't turn my back towards the window because it would make the gorilla angry. I slept on my back for about 3 years before I finally came up with the theory that the gorilla now sat outside my brother's room. ;)
A childhood belief about monsters

others believed things like this
- I used to think that if a gorilla pounded its chest it liked you.Anon
- I thought a Monkey was just a baby Gorilla and when they grew up their Tails fell off!— Brainhead
- For the longest time I used to believe that "Dracula" was a gigantic gorilla with fangs, not unlike King Kong.— Mark Cidade
- I was convinced that Gorilla soldiers in Vietnam in the 70's were real Gorillas attacking other Soldiers.— Mario
- that Guerilla Warfare was called "Gorilla Warfare" and it's about fighting gorillasAnon
- I used to believe that the moon lived on top of our house because I could always see it from the window.— Classic NYer