My dad has this weird belief that an autoharp is actually called an altoharp, but he pronounces alto to rhyme with balto. We used to argue about it a lot. I only heard him say it correctly once. He played one when he was a kid, and I think he misheard what his teacher called it. I think of that and laugh when I play it.
A childhood belief about speaking

others believed things like this
- I believed that the breed of dog called Boxer was called that because they could stand up and box.Anon
- I used to believe that people from Holland were called "Hollish", like people from Poland are called "Polish"— Sally
- I used to think that adult kangaroos were called Kangas and that child kangaroos were called Roos. Anon
- I used to think thunder sounds were called "Boombies" and I would say
"Boombies!" if I heard lightning.— James the Great - The song called heart of glass mixed me up as a kid. I heard "Heart and ass". — oops
- I used to think that board games were called bored games because you play them when you're bored.Anon