Similarly to another post here, I thought the lyrics to Madonna's 'Erotic' were 'hey Ronnie, hey Ronnie, put your hands all over my body'. I didn't realise until a couple of years ago what they actually were (I'm 17 now).
A childhood belief about misheard lyrics

others believed things like this
- I similarly thought that "Proud Mary" included the lyrics "pumped a lot of tanks down in New Orleans."— Larry
- I use to believe that a "Prima Donna" was "Pre-Madonna"---someone before Madonna's time.
— Lacey S - Phil Collins song "I missed again" - I thought it was "I pis*ed again" - didn't realise he was an alcoholic?!Anon
- When I was eight, I loved Madonna's "Papadompe Beach." Didn't get why she was in trouble, though....— tncatboy
- When Madonna sang "let the choir sing" in "Like a Prayer", I thought she was singing "love by proxy"— Kristen
- I used to think the olden days came once every couple of yearsAnon