I used to think that clinical depression was called "cynical" depression.
I thought "unrest" was the opposite of rest. And, since I hated resting, I thought it was a good thing.
I also thought "uneasy" meant "hard" or "difficult".
I forgot the expression "not cricket", so I said, "not tennis" instead.
I mixed "confidence" up with "competence" so when I was watching an episode of a kids' show that involved the idea of "losing your confidence", I was like, "But she didn't lose her confidence! She's still good at it, just too nervous to actually do it."
When I was little I thought it was literally possible to "waste your breath". Like, you could actually talk too much and would not have any air left for speaking, and you'd not be able to talk again for the rest of your life.
I had these pajamas that were too loose for me and my mother called them "loosies" but I thought she was saying "Lucy's" and the reason they were too big was because they were meant for someone named Lucy, not me.
I thought that "losing your cool" meant you weren't cool anymore (as in weren't awesome) so I felt offended when my mother told me I'd lost my cool.
I thought that people only said, "Guess what?!" when delivering good news. So when Dad said, "Hey, guess what?! Eva broke her arm!!" (Eva is my friend and she's OK now, this was years ago), I was shocked at him and wondered why he thought it was good news that my friend broke her arm.
I used to believe that the word "artificial" was actually "art official," like artifical flavored candy was some sort of official art or something.
For a while I believed that saliva was a naughty word to say, because it seemed like a private bodily fluid that you should not mention in public.
I thought that when people talked about skyscrapers they were referring to the jet airliners that I had always seen flying overhead leaving behind them white scrape marks on the sky. My brother corrected me one day when I pointed up and said, "Look, there goes a skyscraper." After he told me that it really meant a super tall building I thought that was absurd, because a tall building doesn't leave a scrape mark!
I used to believe GPS stood for Ginormous Processing System.
I used to believe the word seal had two different spellings. If you mean the animal, you'd spell it "seal" and if you mean the rubber band thing used to close lids, you spell it "seel".
I thought that exorcise and exercise both meant the same thing
I heard the word "pundit" a lot when my parents watched the news, and figured it must be a type of comedian who used puns all the time. I thought it was short for "pun bandit".
I used to believe the world spoke English except for French when I was little boy. I thought only the French spoke French. In the end one day a German spoke to me...
I used to think that the baby slings were called carrions.
When I was little, like 6-7 years old, my dad would sometimes discuss something late at night that I heard as "horse bath".Not really sure why that was a discussion but you never know. -\_(:/)_/- So the next day I went around telling everyone at school that I knew what a "horse bath" was when in reality it was actually "whores bath" and that I had gone around telling everyone I knew about them. Needless to say, I got a good number of calls home and never made that mistake again.
When I was laughing hysterically at something, my mom would ask me "What's so funny that's making you laugh so much like Hanina". I had no idea who "Hanina" really was, but I thought it was the name of some girl that my parents knew who liked laughing a lot. Later, I found out that she meant "laugh like a hyena", not "Hanina", and a hyena was an animal that laughs.
I used to pronounce the word "Computer" as "Crocuta"