Insecurity, coupled with a lack of consideration for others, is an unpleasant combination.

Like many of us, the guy is insecure: He makes himself feel better about himself by finding ways to show his "superior knowledge." He is in a constant competition with others, comparing himself to them and finding some meaningless way to feel like he is the winner.

I find myself doing this when I am stressed by events in my life. I imagine that many here share this affliction. But most of us recognize this as a weakness and have the courtesy to keep our mouths shut.
Brent