I remember sitting on my Dad's lap when the Beatles' song Eight Days a Week first came out. I was confused because someone had told me there were really only seven days in a week and I wanted to believe the Beatles.
A childhood belief about misheard lyrics

others believed things like this
- I thought that "tomorrow" was one of the days of the week— Frank
- I once refused to believe in Thursday. I'd heard there were seven days in a week, but could only name six.Anon
- I always thought that after 1999 it would be 1990 again, but with different months and days of the week
— optional - The Beatles song "Ticket to Ride" always came out "She's got a tick in her eye."— Kurt
- When I was little, I thought the Beatles really were bugs.— Spongekid
- the beatles song 'mean mr mustard' says "shes a real go-getter", i was sure it was "shes a real coconut"...— sally