I was so paranoid as a kid when it came to swearing. I truely and actually believed that the phrase "shut up", even in a joking manner, was considered cussing.
Whenever I got mad on the playground, I would always yell "BE QUIET!!!" instead of shut up. Needless to say, that didn't really work. ^-^
But nevertheless, it wasn't until the fifth grade until I started saying "shut up".
A childhood belief about swearing

others believed things like this
- I believed that "shut up" was cussing so i said it 1 million times— Kyla
- i used to believe that dragonflies would sew your mouth shut.Anon
- i used to believe that drangonfly's would sew your mouth shutAnon
- I used to believe that “shut up” was a swear word.Anon
- I used to believe that if you told a lie, Dragonflies will come and sew your mouth shut. For real.— Casey
- I used to tape my mouth shut at night in case a spider would come along and make a web in my belly.Anon