I told my dad he was pathetic once and probably called him other names (I can't remember, it was ages ago) and when I was about 4 I called a boy in my school "bossyboots" (lol! xD), but that's about it. I don't make a habit of insulting people.
I'm usually not mean to people, but one time this kid was really pissing me off. I think I said something along the lines of: "Just because you have Epilepsy doesn't mean you can be a fucking douche-bag to EVERYONE. Piss off asshole." Mhm~ He always got away with stuff because he has Epilepsy, and I was just about done with that.