I used to believe that the lyrics in Manic Monday said "All of my life why did my mother have to kidnap Sacha Distel".
It was only while doing karaoke in the pub one night that I discovered the true lyrics were "All of the nights why did my lover have to pick last night to get down."
I now believe my lyrics are better.
A childhood belief about misheard lyrics

others believed things like this
- Actual lyrics: "I've never been your beast of burden"
My lyrics: "I've never been your big suburban"
— Big Suburban - I always thought the lyrics in I'm Blue were "I could beat up a guy"— Trisha Gaurav
- I thought the lyrics to "Single Ladies" were "If you liked it, then you should've put your name on it."Anon
- in the song with the lyrics "take your passion" my sister used to always think it was "take your pants off"— Steped
- I used to think Elvis' "I'm All Shook Up" was "A Mushy Cup". How sad of me to confuse the lyrics of a king...— Sad, Sad, Girl
- I thought the lyrics to "We're going to Ibiza" by the Venga Boys was "We're going to eat pizza"— ShannonOfDoom