I used to believe that being a good soldier meant doing everything they told you.
I thought that the Titanic rammed into the iceberg on purpose, as I thought they figured the ship was so tough it would just plow through it unharmed. I didn't learn the truth till a few years ago. I think I thought this because of how much they bragged about it being unsinkable
When I was a child I used to believe that the world was black and white, like in the old TV's that first appeared.
When I was younger, I used to think, in the past, there wasn't color because the photos were in black and white.
German tiger tanks shot out tigers, the invading army would get mauled to death by all the tigers
Before learning about the Cold War, I thought that the space race was actually two spaceships, one from America amd one from Russia, that launched at the same time to see which one would get to the moon fastest.
I used to believe that Clint Eastwood actually lived in the old west, but I also knew that he was still alive in the present day (this was around 2009 or so), so you can imagine how old he must've been if that was the case. I probably believed this because the main place I learned about him from was Back to the Future.
I used to believe the Wall Street Crash of 1929 was a literal car crashing into a bank.
I thought “guerrilla tactics” meant fighting like a gorilla— beating your chest and that sort of thing.
I thought the Civil War was between North America and South America. It was only when I was asking my mother how the "north" could blockade the "south" when there was just so much available coastline that I figured out what was wrong