why do some players show their cards during the play of the hand?

[DrewOnTilt]

Today at a B&M game I sat next to a guy who showed me his cards during the play of the hand nearly every time I had folded ahead of him. Big pair? He shows them to me. Flush draw? Show it. Bust hand? Ditto. It got to be very annoying.

This is not the first time that this has happened. Why do some players feel the need to do this? Do they think that they are showing off their poker prowess or intelligence (this guy tonight had neither)? Do they think that I care when they miss draws? Or do they just get some kind of satisfaction out of showing off a big hand (or relief from misery from showing off a bust hand)?

And most importantly, do they simply not realize that astute players may be able to read the hand via my reaction to it?