My cousin used to think that the lowest number in existence was negative zero. He knew that negative numbers were all lower than positive ones, but he wouldn't believe me when I told him they were in reverse order.
A childhood belief about counting

others believed things like this
- I used to believe that numbers had gender, that the odd numbers were boys and even numbers were girls. — Evelyn
- I used to believe that after the number "ten" came the numbers "tendy-one, tendy-two..." etc.Anon
- I used to believe that aeroplanes could reverse when they are flying. Anon
- My cousin's mom told my cousin that pop makes you short. He probably believed it.— Molly
- When I was about 5, I thought that English was the reverse reading of Turkish.— sel
- when i was little i believed that your social security number was the number you were born on the earth — christine