Not really mine - when my mother was a kid there was a pop song called "I Want You Back". Apparently several of her friends thought it sounded like "I Wash Your Back".
A childhood belief about misheard lyrics

others believed things like this
- I used to believe that if I cut my dolls hair it would grow back just like mine did after a haircut. — diamond girl
- I thought that the song "Hands off she's mine" by The English Beat was actually saying "Anton, she's my aunt"— Nate
- I used to believe that all parents were called "Inge and Dirk", just like mine— eva
- My friend's sister believed the lyrics to Gazza's "Fog on the Tyne" were "Fog on the dinasaurs mine all mine"— Suzanne
- When I first saw "brb" on an im I thought the person burped, not that they would be right back.Anon
- I thought your fingers would grow back if they got cut off— Nate