I used to be sure that Elton John and John Lennon were the same person - I'd heard some Beatles as a little boy, but knew that no one but a Beatle could have sung Rocket Man. It also made sense since Paul McCartney had 'Uncle Albert' out around the same time.
A childhood belief about pop stars

others believed things like this
- I used to think that the Beatles broke up when John Lennon died.— Shirley B.
- As a child I used to think that Olivia Newton-John and Elton John were married.
Boy, I was way off.— Lisa - I used to think that Lenin and John Lennon were the same person.— Melanjolly
- As a child, I thought that Olivia Newton-John was Elton John's wife and Juice Newton's sister.— Connie
- I used to think the lyrics to Elton John's Tiny Dancer were "hold me closer Tony Danza."— kstawitz
- My friend used to believe that the lyrics to Elton John's "Tiny Dancer" were:
"Hold me closer Tony Danza"— I'm with stupid