I used to believe that when a couple was getting married, in their vows they said "With this ring I be wed" instead of I thee wed.
A childhood belief about marriage

others believed things like this
- I used to think that when a couple got married and went on their honeymoon, they took a vacation to the moon.— Jen
- I used to think Uncle Ben and Aunt Jemima were a married couple. — l stu electtirc boogaloo
- that the word "couple" as in "a couple of items" was synonymous with "several", rather than "just two".— Blair A. Petterson
- i used to believe nuns were married to jesus and priests were married to mary.— sunshine
- I used to think the olden days came once every couple of yearsAnon
- i used to believe, that if you were married you were a mum and dad— Fay