I've spent many years training in shinkendo (japanese swordsmanship), and while I'm usually pretty good about it, I will admit sometimes my pride can get the better of me.
I especially loathe the foaming-at-the-mouth anime kids "omgkatanacool". The last time I accompanied a friend of mine to a game con(we're tabletop gamers) I ran into some dolt dressed as somebody from an anime waving a foam sword around. Since I was in my training uniform at the time, because it was comfy and I felt like it, this guy proceeded to spout about 90 comments on how I look like this dude from this anime but you're missing this, or the wood stick I was wearing looks nothing like a REAL katana(which amused me, i was wearing my bokken, and he pronounced it kuh-tuna).
In retrospect I probably shouldn't have been such a dick, but I leaned over, got real close, and told him rather sarcastically, "Kid, I have no idea what the fuck you're talking about, I don't watch anime, and I'm not dressed as anybody. One of these days, you should grow up, and then maybe you can learn to use a REAL(putting the same emphasis he had on the word, for extra sarcasm) sword. Now shoo."