I used to think that the chocolate/vanilla/strawberry mix ice cream was called Napoleon (instead of neopolitan) and couldn't understand why a French emperor got an ice cream flavor named after him.
A childhood belief about general

others believed things like this
- i used to think that napoleon invented neopolitan ice creamAnon
- I used to be believe that vanilla ice cream was the "healthy" flavor.Anon
- up until this morning i used to believe that "neapolitan" ice cream was "napoleon" ice cream. I'm 15.Anon
- 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
- I believed clouds were vanilla ice cream.— Ichi