I used to believe that, once boys reached the age of eleven, they would begin turning into monkeys. Their brains would detiorate, and they would grow hair in strange places. They'd perform monkey-like actions.
Hey, I wasn't too far from the truth. :)
A childhood belief about getting older

others believed things like this
- that blackouts were caused by evil monkey's turning off all the lights.— key
- I used to believe that people's brains differed in colours. I always wanted purple brains for some reason.— Katrina
- I believed that if you ate a piece of your own hair, a new strand of hair would grow on your head.— Ryo
- if you drink water from unsafe places, frogs will grow in your stomach...— Olivier
- I used to believe that after I cut my barbie's hair, they will grow again. They've never grown :(— Duda
- I used to believe that my head was filled with hair waiting to grow.— Poppy