When I was kid I thought the year numbers would roll over eventually i.e after a certain year it would start over from 0 or 1. I found out the truth when it was shortly after new years day (I think it was 1991) and I asked the teacher if it would ever be 1990 again and she said no. For some reason this really bothered me at the time..
A childhood belief about general

others believed things like this
- I believed that pigs could actually fly. I'm 13 and found out this year that they can't.— Boy I'm Blonde
- I believed that numbers eventually just ended. That they stopped somewhere after 1000.— Jamis
- I only found out last year that a pony is not a baby horse.— Mescaline Frumblethond
- Abba - Happy New Year
"Kangaroo year,
Kangaroo year..."— Santa Puncher - I thought that 1983 went on for 3 years - had to ask my sister who decided how long a year lasted.— Sally
- When I was in elementary school I use to think that teacher lived at school at their desks all year long.Anon