Up until I was like 10, I thought anything you bought that said "pre-" meant it was done half way and you had to finish the other half (like a pre-sharpened pencil was only sharpened half way).
A childhood belief about speaking

others believed things like this
- As a kid I used to believe that when you sharpened your pencil, the eraser on the pencil grew.Anon
- I used to believe that your belly button was what held your top half to your bottom half...— Debelouwho
- I used to believe that when your pencil ran out of eraser that if you sharpened it it would grow a new eraser— Nikkie
- when i was4 and a half i thought i would be 5 feet in kindergarten— Katrina S.
- An hour and a half is exactly the same as half an hourAnon
- I used to think you could die if you jumped half way down the stairs. Anon