This is a rather stupid one lol, but I used to think that foreign schoolkids, like ones from Kosovo or somewhere like that, would have to have 'special lessons' with speaking English. You get the idea.
A childhood belief about foreign languages

others believed things like this
- I used to believe that anyone speaking a foreign language translated it into english in their head— galen
- I used to believe that all Christians were English and all other religious people were foreign.Anon
- I was shocked when I found out that dogs in foreign countries didn't know English commands.Anon
- I heard my mum talking about foreign people, and I later asked, "have you ever been to Foreign?"— Kia
- I used to believe that people who were speaking foreighn languages were just speaking gibberish.— Zoe
- I used to think that even people who spoke something other than English, thought in English— Peaches