Coming Off As Arrogant

I've been thinking about that douche from a few weeks ago and how he made jabs at me throughout the conversation.  He's not the first nor will be the last to do so.  Every year I have to deal with one insecure moron after another.  Bobby, my idiotic room mate during my first year here, was one, several others throughout high school and middle school.  It's pretty annoying that these idiots keep popping up over and over again, constantly trying to boost their own ego at my expense.  The only upside is that I'm getting better and better at waging psychological and information wars against these idiots and shattering their egos.  Hell, breaking Bobby took only 7 months, a new personal record.  But aside from these morons, every now and then I get snooty cashiers or clerks that act like an ass to me even though I've just met them.  Either I'm a crappy customer service magnet or there's something about me that is making them act like that.  It could be because I come off as arrogant.

I'm not sure if it is and I don't know what it is I'm doing that's giving off that vibe.  Should I smile more?  Should I be more relaxed?  I don't know what I should do, but it is an issue I should focus on.

Note to self:  Don't be arrogant.