I used to believe that the song "Amazing Grace" was about an old, blind bag lady who begged for money on the streets. One day, she had enough money for eye surgery.
Thus - she was once blind, but now could see.
Someone told me that was the meaning of the song.
A childhood belief about hymns

others believed things like this
- I used to think the lady behind the cash register at the A & P got to keep all the money in the drawer.Anon
- I used to believe that blind dates were dates for people who were blind.Anon
- I was told that if you went to brd with your sox on you would go blind.— Frank L
- I used to think that Chris de burgh song Lady in red was Lady in Bread
— Omega-R-Fox - I used to think the song "dude looks like a lady" by aerosmith was "doodles like a lady"— I used to believe
- When I was a little kid I used to believe that tissue paper was money and that you could have a box of money.Anon