I'm an American. When I first learned about the U.S. Civil War in school, I seized upon the alternate name "War Between The States" and took it too literally. I got into my head that the war unfolded as every single state going to war against every other state that bordered it. So the entire United States was a big nest of shooting border wars!
Fortunately I held this belief only briefly, but the lasting effect is that I still have a distaste for the name War Between The States.
A childhood belief about wars

others believed things like this
- I used to believe that China was attached to the United States somewhere up near Washington state.Anon
- I grew up in Hawaii, and was pretty sure that our country, the United States, was the fiftieth stateAnon
- I used to believe that America was one of the states of the United States.— Limor
- I used to believ that "Shooting the Bull" literally meant what it states.— DJ
- I used to believe that the United States covered almost the entire planet.— RAB
- i used to think France was in the united states
— TY