I used to think that when you became an adult (at about the age of 13) you had to change your name to an 'adult' name. This was because I had never met an adult with the same name as my kiddy friends, or vice-versa. It seemed very plausible.
I think this was made worse by asking my mum how old people were when they changed their names, and what adult name I would like to have. Misunderstanding me (she thought I didn't like my name and wanted to legally change it) she told me it could only happen when I was grown up.
A childhood belief about names

others believed things like this
- When I was a child, I thought that grown-ups were adult.— Gloria
- My brother thought that one adult was a dult and that one alert was a lert.Anon
- I thought adultery was when you acted too much like an adult as a kid and wondered whats so bad about that?— Butch McFear
- I always thought there was a drinking age for coffee, because it was an adult drink like beer and wine.Anon
- that when I grew to be an adult my parents would be children.— Rainbow
- when I was about six I remember asking an Adult what Mary did before she was a statue....Anon