One time when I was around kinderkarten age, my mom told me that I had a lot of nerve. I already had some idea about what nerves really were though, so I didn't realize she was criticizing my behavior. In fact, I had no idea why she was saying it.
Another time, my dad asked me if I respected him, but I had no idea what that word meant. It sounded like "resent" though, so I figured it had a similar meaning and said no thinking I was being polite. He then spanked me and gave me a long lecture about why I should respect him, but it never occured to him to tell me what it meant and it nevered occured to me that I may have misunderstood the meaning of the word, so I was extremely confused about why he wanted me to resent him so much until I finally learned its true meaning a few years later.
I loved dinosaurs and everything about them, so whenever someone said "drastically," I misinterpretted it as "Jurassically."
I also thought "truck" was "chruck" and "track" was "chrack," until about first grade. After learning about the sounds that different letters make, I thought it was very strange that everyone else insisted that those words were spelled with a T instead of a CH. The same goes for "train / chrain" and pretty much any other word that begins with TR.