In the chorus of Greenday's "Holiday," the lyrics go "I beg to dream and differ." When I first heard it, I thought it was "I beg to Truman."
I thought "why are they talking about dead presidents?"
A childhood belief about misheard lyrics

others believed things like this
- I swear I heard a Disney Channel/Radio Disney song where the chorus was a repeated “Damn it”— SpengBab
- i thought in elton john's "tiny dancer'' the chorus was "hold me closer tony danza"— d.a.
- I thought that life is a dream and when you die you wake up (maybe it's true who knows?)— Naos
- I thought the holiday was called "Merrychristmas" so I would tell people "happy merrychristmas"Anon
- When I first heard Stawberry Fields Forever, I misheard the lyrics as Strawberry Fields For Trevor.— Matt
- Actual lyrics: "I've never been your beast of burden"
My lyrics: "I've never been your big suburban"
— Big Suburban