Assumptions from history
I've gone through life thinking the "Stars and Bars" was just like what you would find on the top of the General Lee from The Dukes of Hazzard.
And I was wrong.
The thing painted on the car wasn't the Stars and Bars, it was the Confederate battle flag. The Stars and Bars was the flag of the Confederate States, which looks nothing like that!
It's just one of those weird things that you figure you just have always known, but you've been wrong the entire time.