My most recently kept-up circle of local (meaning non-Internet, non-distance, as most of my friendships actually are do to this constantly mobile world of ours) friends are quite awesome people, but they are all more extroverted than me. We used to all be woefully underemployed together, so I had more time to be extroverted with them, but I was the schmuck who got a full-time job first.
I am unabashedly and undeniably on the introvert side of the scale, but can be quite functionally extroverted in the right circumstances. Incompatible schedules make this very difficult, however. I want to spend time with just a handful of us, that's fine for them sometimes but sometimes they need more excitement and more people. Sometimes that's fine for me too but then I have to go home and recharge, and while I'm doing that they are still out finding more things to do and more people to do them with. There's no reason I should feel like I have to come along on all of that, of course, but I find that new acquaintances and new plans are constantly being made that I might want to join in on after a re-charge but by then it's already too late. I'll propose plans of my own from a position of being out of the loop and secondary to what is going on, thus I am rarely taken up on them, and I have to remind them to remember to include me on things they are planning that I might love to do after being re-charged. The whole experience makes me feel somewhat socially breathless, like I am constantly fighting to keep up.
There's a little bit of my frugality entering into this too, because I am unwilling to spend money on several social events in one night or even one week or hell even more than once or twice a month, and while I wasn't working this was especially important and especially damning because I had so little money and yet so much time. All together I sometimes find myself feeling stuffy and prudish and boring, compared to they who are free and fun and infinitely interesting.
Introverted friendships have always served me better: more depth, more doing the kind of activities I want to do in a group size that is comfortable for me, more commitment to a friendship across distance, since the trend in this place is for young people to be unable to find jobs here and thus leave. In some ways being forced into more extroversion has been good for me, certainly seeing and understanding differences in other people has been. But trying to force my friends into a friendship mold that works for me, or trying to force myself into a mold that works with how they work...probably isn't good for anybody.
Well, turns out they're all moving away too as they too, secure jobs that aren't in this jobless town, so looks like I'm in the general market for some more compatible local friends regardless.