In Nirvana's song "Dumb" I used to think the lyric "I think I'm dumb" was "Agatha don't." And for years I wondered, what was Agatha doing that was making Kurt Cobain so miserable?
A childhood belief about misheard lyrics

others believed things like this
- Remember the old Tubes song "White Punks on Dope". Thought they were singing "White Folks are Dumb"
— WailerMan - I used to believe that every death had an autopsy ;-;
I was so dumb as a kid lol— Brii - when i was like 6 i thought only little kids my age could have long hair. dumb....lol— candy
- i used to think that a'quarterback' was some guy who ran around with a giant quarter on his back! i was dumb— :]
- I used to believe that if you farted really hard, you could fart a hole in your pants. How dumb was that?— stargirl
- I always wondered why shepherds washed their socks by night. (correct lyric: watched their flocks)— MaggieNJ