The "Gift" of Winning Arguments

I was in a McDonalds late at night (late enough that nothing else was open) with nothing to do but thumb through a yellow pages that was sitting there (well, and eat of course). Saw this funny quote in there from Dave Barry, whose work I love, when its censored (as in the newspaper). May I know how to debate well, and -- especially, most importantly, and for crying out loud -- know when not to.

"I argue very well. Ask any of my remaining friends. I can win an argument on any topic, against any opponent. People know this, and steer clear of me at parties. Often, as a sign of their great respect, they don't even invite me." (Dave Barry)