I believed that Justin's line of the song 'Four Minutes' by Madonna was "Keep it up, keep it up, Don't be a Britney, Madonna" referencing Britney's meltdown and how Madonna has to keep on going with her career to avoid a similar fate! I'm still not sure what the real lyrics are.
A childhood belief about misheard lyrics

others believed things like this
- I use to believe that a "Prima Donna" was "Pre-Madonna"---someone before Madonna's time.
— Lacey S - I used to believe that the word prima donna was actually pre-MadonnaAnon
- I used to believe that Madonna's Papa don't preach was pop-a-long priest— Mark "lyric master" Rowbowtohme
- When I was younger I always imagined Madonna and Micheal Jackson would get married.— munky
- 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