I used to believe that people only grew upto age 10 as I hadn't been taught how to count beyond 10 at that age.
A childhood belief about getting older

others believed things like this
- I thought that Count Dracula was the count from Sesame StreetAnon
- I used to believe that it would take forever to count to 100— Jeff
- I used to think wrinkles came about because people just grew too much skin.Anon
- I used to believe that people only grew, physically and in age, on their birthday. — Aretia
- I thought plants only grew when people were not looking at them.Anon
- when i was in kindergarten i used to think that 100 was the highest someone could count!— Jessica