When I was little I saw the word "applause" and thought it said "applesauce"
I used to think people read books because of that overwhelming smell of the pages that you can bury your nose in, rather than the actual subject!
I used to think Jane Austen was related to the Bronte sisters, maybe like their cousin or step/half-sister.
I thought the word lackadaisical was something to do with lacking daisies.
When I was learning to read, I pronounced "fire" as "fury" and "crocodile" as "croco-DEE-lay".
This one is actually my uncle. He lived with Granny and Granddad and my mother and aunt in a house next to a butcher's shop or something that had "hydra" written on the sign.
My uncle couldn't read back then and thought that the sign had his name on them.
I used to get "jaw" confused with "palm."
When I was about twelve or thirteen, my mother was reading me The Odyssey, and at one point, Queen Penelope has these men who want to marry her because they think Odysseus is dead, and they say, "We'll draw lots". I didn't know what that meant, so I thought it meant they'd draw (as in sketch) a lot of Odysseuses.
I learned about opposites from Sesame Street and naturally assumed EVERYTHING in the world had to have an opposite. Spanish was the opposite of English, the sun was the opposite of the moon, candy was the opposite of vegetables, recess was the opposite of classtime, rollerblades were the opposite of bicycles, and cats were the opposite of dogs.
I used to believe that "sue" meant murder, so in movies when someone is getting sued I got really confused
I used to believe when you'd see a company sign that says "Est. 1928” it meant they estimated the company was founded in 1928. I always wondered why some companies had to estimate when they were only a few years old. Much later I realized est stands for "established" and not "estimated".
I used to think that the word "adjacent" was pronounced "add jassent"
When I was about 5 years old, I thought that "Scarlatti" was a type of Italian pasta, sort of like spaghetti or noodles.
I first saw the word "Lisztomania" in a "grown-up"(a book that doesn't have many pictures) book I was reading at the library as a kid. I didn't know what it meant at the time, so I assumed it was a country or a type of dance or something like that...
I used to think that oxymoron had something to do with oxygen...
Until I was in 4th grade i thought choir was pronounced "chore"
I thought the British town Reading was pronounced "Reeding" instead of "Redding".
When I was five years old, my mom had a copy of a book titled "What Was Good About Today?" I thought the title meant that "Good" was the name of a TV show and that the author was asking what that day's episode was about.
There's a Captain Underpants book in which the heroes put the title character under a placebo effect, which they misidentify as a "placenta effect". I had heard of the concept, but the joke went over my head, and for years I referred to the phenomenon as "the placenta effect".
I once saw the phrase "infrared light" in a physics book I had. I thought the light has been infrared, as if "to infrare" (pronounce inf-rare) was a verb.