My family used to listen to Broadway show tunes records. A favorite when I was about 6 years old was "West Side Story".
In the song "America", the Puerto Rican boys and girls argue about whether life in America is great, or not. I always believed that once I was older, I'd find out who "Morris Amalfi" was and why it mattered that he was in America:
"I like to be in America, Okay by me in America, Everything free in America, Morris Amalfi in America!"
The correct line, of course, is "For a small fee in America".
A childhood belief about misheard lyrics

others believed things like this
- I used to believe all of North America was Canada and South America was USA..— Daria
- When I was in kindergarten, I thought the last line of "America" was "Great God our kid." — CC
- I used to think we lived in America.— Amy, Britain
- I used to believe that The Mall Of America was in Canada. — Adam
- I used to think that America was the only country that had cars.Anon
- I used to believe that America was a state near the one I live in.Anon