When I was about 6 I knew a mute girl at primary school. I used to believe that people had a limited number of words that they could pronounce in a lifetime and once you'd used them all up, then you became mute. From then on, I paid special attention not to waste words.
A childhood belief about speaking

others believed things like this
- I used to believe that the words to Michael Jacksons "Liberian Girl" were "librarian girl".— Paul
- I used to believe that all four-letter words are bad words.Anon
- When I was at primary school I used to believe you could only marry someone who was the same height as you!— Lucy
- My mom used to say that if I said bad words, poop would appear in my mouth— Nina
- I thought "prison" and "prism" are the same words as each other.Anon
- In primary school, a whole bunch of kids including me believed that watermelon seeds contained ants. — Caff