Back when I was in school, it was used as an insult towards goths, emos, and the like. All the people that wore dark clothes and were melancholy and what not. I've also seen it used towards people trying too hard to be cool and stuff like the "Nothing Personnel, Kid," meme. Now it seems to just get thrown around at everyone. Mostly towards people just being assholes... So, what even the hell does it mean?