I'm not somebody who needs social interaction to be happy, I don't like bumping into old school friends when I'm out with my friends for example, I'm not really interested in 'how they are' and 'what they've been upto' which is a problem as I do like these people, I'm just not interested enough to make them believe it. This is something that I sometimes wish would change, I'd like to be more interested in people outside my immediate friend group (about 8 of us) but I just can't do it.
I'm a little shy when approaching new people which annoys me too, I'm usually fine once I'm off the mark, it's just the initial meeting.
I guess sometimes I wish I was a little more sociable in general, it's not become a problem yet as I have great friends and a great girlfriend etc. but I might try working on it.