I refuse to dumb down my vocabulary unless I’m talking to a literal child, and even then not as much as most people do. On the plus side, I’m really cool about defining words people don’t know without being an ass about it.
I insist on precision in my own speech–this drives my SO insane. He’ll ask me a general question (along the lines of “so x is y, right?” to which I’ll respond “no, x is similar to y but there are some differences and even though x = y is nearly accurate, it’s not completely so,” but a bit less pedantic, usually) and I’ll give him a very precise answer that to his mind contains no differences to a simple yes or no answer. He takes umbrage at my longer answers and maintains that I’m saying he’s “wrong” about something. Not true, just precision. He also gets pissed when I explain at length that “right” and “wrong” don’t enter into it, it’s purely a matter of different means of expression–of course, this is perceived as yet another form of attack and putting him in the wrong and the cycle continues. We’ll probably end up separating over this eventually, again.
I drive old, weird cars by choice and have no interest in buying something newer or less crotchety. Sorry, I like my cars!
I also get the redass from coworkers when I figure something out or streamline a process–what is up with that, anyway?
My sense of humor gets me into trouble quite often–apparently I find many things screamingly funny that many other people regard as sacrosanct, oops!