Arrogance vs. Confidence

I never used to think of myself as arrogant. Certainly, I know what I know and have no doubts about it - afterall if you didn't think you were right, you wouldn't think it would you?. But arrogant? Moi?

Not too long ago, I was visiting my sister in sunny California (yes, my luck held out and the 8 month long dry season ended while I was there...) and we stopped by a typically trendy drinking establishment. Feeling self-deprecating, I ordered an "Arrogant Bastard" - a delightfully poignant brew with a good hoppy finish. To my dismay, my sister, my wife and even the waitress made noises of approval! I can understand my wife and sister (two separate people, don't let your WV tenancies show) doing that, but for a waitress...!!

Haven't been able to shake that encounter... been dwelling on it on and off for a few months... Am I really that arrogant, or do people just have a problem with my confidence? Such thoughts naturally lead me to ponder the difference between arrogance and confidence.

Dictionary differences aside (arrogance, confidence) I have come to the following conclusion: Arrogance is when someone thinks you think you're better than they are while confidence is when they agree with you. All in the eye of the beholder, you see? Am I to be blamed for being arrogant, or praised for being confident? Strange is it not, that you can be over confident but not over arrogant?

Is it arrogance or confidence that leads people to do things like this: