Been to a lot of concerts, both big and small (and have played my fair share as well).
Something about being at the concert, where everybody has a common goal: watch the band, helps me a lot. However I don't really socialise a lot at concerts, same as with any other situation, really. It just makes it much easier to be myself at gig though, just go completely up in the music.
Pits are esspecially fun when you feel like it, as you get a real go with the crowd thing, I don't know how to describe it better. I've also done a couple of stagedives and crowdsurfing (though less crowdsurfing than stagediving, so I guess you can imagine what that means

).
After playing a gig myself I generally also have quite a boost in self-confidence, so that's really good. But then at the same time I go into neurotic mode and I really enjoy just being left alone packing in all the gear (after it's been moved from the stage). And then it's just a question of riding the high until the unevitable low comes, which is pretty bad...

Before the show I have a really strange way with getting nervous. Like small shows with like 10 people in attendence make me really nervous, while large shows 100+ people don't really make me nervous at all. It's really weird, but I guess with just a couple of people there it's more personal, or something.