I was convinced that Abba's 1980 number 1 hit "Super Trouper" contained the lyric "I was sick and tired of everything, When I called you last night from Tesco's".
It's actually "...from GLASGOW"!
A childhood belief about misheard lyrics

others believed things like this
- I used to believe that when i died it was like a super mario game... I had a certain number of lives.— David...waffles
- I always wondered why shepherds washed their socks by night. (correct lyric: watched their flocks)— MaggieNJ
- I used to believe that the Super intendant was the Super Nintendo.— Lecia
- I thought pretending I was sick to stay home from school was called cookie not hookie.— Jen
- When I was a kid, I thought the musical Mamma Mia did songs from the A*Teens (the teenage version of Abba)Anon
- when i was little i believed that your social security number was the number you were born on the earth — christine