This wasn't mine, but rather one a math teacher told me:
We he taught 6th grade, he had a student come up and tell him, after the first day of class, that Elemtary School Math was where you learned to add, subtract, multiply, and divide numbers, and Middle School Math was where you learned to add, subtract, multiply, and divide letters instead.
A childhood belief about classes

others believed things like this
- I used to believe that 7 times 12 was equal to 83 or 84, depending on the math problem.— Eric Swensen
- I used to think my elementary school gym teacher's name was "Jim Class".— Brandon Campbell
- A[n] nth grade teacher only had to finish the nth grade when he or she was in school.— MD Caruso
- When I was in elementary school I use to think that teacher lived at school at their desks all year long.Anon
- I used to think that my teacher lived at school until she came to school late one day. I was shocked!— Wow, you have a life?!
- I learned in the first grade that the Sun was a star just like all the other stars, only it was MUCH bigger.— Geoff