I used to believe eggs were a substitute for a lost bouncy-ball. I would try to bounce the eggs on the living room floor, and when they would crack, I'd assume that egg was "defective" and grab another. Eventually, I figured out that eggs don't bounce but I'd still try it, yknow, 'just in case'.
A childhood belief about general

others believed things like this
- I used to believe that only brown eggs came from chickens. I thought white eggs were made at the store— Destiny
- When I was a kid, I used to believe that cadbury cream eggs real uncooked eggs in the middle Anon
- I used to believe that bunny rabbits hatched from eggs, since the Easter Bunny gave you eggs.— goat
- i used to believe that eggs used to come from humans.Anon
- Rabbits lay eggs— Maria Eduarda
- I used to think cantaloupes were antelope eggs.— watch the fireworks