I used to believe that when you hit adulthood that you had to change your name to something like Betty or Anne, because little kids aren't called names like that.
A childhood belief about names

others believed things like this
- When I was little I used to believe that all old women were called Betty!!— Katie
- I used to believe that Marilyn Monroe and Betty Boop were the same person.— Madame Butterfly
- I believed until near adulthood that when I was 6 or 7 I had actually flown for several feet in my back yard. — Jane S Poole
- Well into adulthood I thought that a local anesthetic meant one from the area near the hospital..— D'sparil
- When me and my brother were kids we used to think that Jim'll Fix it's Jimmy Saville was called Jim'llAnon
- I never did understand why it was "Our Father, who aren't in heaven".— Edith