I used to believe that if you had sex, you had it before you married someone and then stopped after your wedding.
A childhood belief about marriage

others believed things like this
- I used to believe that having children could only happen after a wedding with the person you are married to.Anon
- i used to believe nuns were married to jesus and priests were married to mary.— sunshine
- I used to believe that when I see a flock of birds in the sky, they have a wedding ceremony.— Mr. Used to
- i used to believe, that if you were married you were a mum and dad— Fay
- when I was little I used to think you had to have a baby before you got married!— Supergirl
- I used to believe that woman had to pay to keep their last name when they got married!!!!!!!— Imaginative_Kidd