I used to believe that, when people did the voices for cartoons, they did the animation first, and they had to time their speaking just right.
A childhood belief about cartoons

others believed things like this
- I used to believe that people who were speaking foreighn languages were just speaking gibberish.— Zoe
- I used to think that "cross-eyed" meant that people had X's for eyes, like dead people in cartoons.— Tim
- I used to wonder why people didn't have outlines like they did in cartoons.— Anna
- I used to believe cartoons were real people and animals. They were just wet.— Wendy
- I used to believe cartoons where real people. You can imagine how that went... — Emma
- When I was a kid I used to believe that cartoons were people dressed up in special costumes.— Sarah-Jane