When my dad was little he used to think vanilla was actually plain. Chocolate, strawberry, butterscotch, banana, etc. were all flavors.
A childhood belief about sweeties

others believed things like this
- I used to believe vanilla were albino chocolate.— Alexa
- I used to think that vanilla was the absence of chocolate, not its own flavor.— Gen
- I used to believe that vanilla wasn't a flavor. It just didn't have chocolate in it!— Andrea
- Chocolate, they say, rots your teeth. I believed if you drank chocolate milk, your bones would be brown.— Dellio
- I used to belive chocolate milk came from brown or chocolate cows.Anon
- I used to be believe that vanilla ice cream was the "healthy" flavor.Anon