When I was little, we had one of those potty-training books that tells the story of a little girl or boy that gets potty trained, gets their own potty, etc. The book's choice of words often confused me when I would read it because it used the word "urine" to refer to pee. I had never heard the word before, but I could tell that it referred to pee somehow. When my little sister asked me to read the book to her, she stopped me and asked what "urine" meant. I confidently told her that it was the Spanish word for pee. What a dope.
A childhood belief about foreign languages

others believed things like this
- In first grade, I thought that if I've never heard of a word before, then it wasn't a word.— Destiny
- I used to think people had a "potty mouth" if they had been drinking out of the toilet.Anon
- My brother used to be scared to poop in the potty. He thought that he was pooping out his bones.— Lillyth
- I used to believe that to speak Spanish all you had to do was a an "o" to the end of each word. — !!.-ariel-.!!
- I used to believe that "foofa" was the F-word in Spanish.Anon
- I used to believe if you read a book in the dark, you would go blind.— Ellen