When I was around 4 or 5 is the first time I can remember playing with lego. I'd stay in my room all day and just build build build. After a while I got tired of following the directions and would make improvements on the designs. I also "built" my own friends and talked to them.
In 1st grade every friday we'd have a wheel-of-fortune style game. After guessing "Have a great weekend!" without having any letters on the board yet, I was no longer allowed to participate until at least 5 other children were allowed to answer, those dimwitted fools. [But seriously, "have a great weekend" was the logical choice. It was friday, and spaces matched exactly, not much of a stretch from there...]
In 3rd grade I refused to do "guest, test, revise" [WHAT A SHAM] homework. I told the teacher "Guess, test, and revise is the dumbest thing I have ever seen, and I watch Power Rangers." That resulted in my first trip to the principals office ever. I told her I still wasn't going to do it until she showed me the "real" way. Turns out the real way is called algebra.
In 6th grade I told my science teacher her description of an atom as a "mini solar system" was a lie, and was an outdated interpretation since the 1930s, and I could not in good conscience answer a test question in which I knew I was putting down an incorrect answer.