Connecting with people

I've found that through the years I've spent a lot of time getting to know lots of different people. The best I can say for my efforts is that I think I'm missing something on some level with regards to how I communicate with and understand people. I usually have nice conversations, maybe even see the person multiple times just going to and fro. I rarely however want to make the effort to keep up the relationship. Somehow it just doesn't seem important to me to maintain ongoing relationships with more than a small circle of friends. I guess I might benefit from developing better relationships but I can't figure out what the missing element is. Perhaps its because I'm introverted, however I like chatting, and find it easy to talk to people at parties.