I think the feeling of anti-social behaviour that comes with aging is merely a consequence of comparing one’s current life to college and slightly after college life. I think most people form deep ties with friends during the college years and the people you meet there-after may or may not be as fulfilling.
Furthermore, and we are getting older and our choices change because our perception of values change — sleep and/or work seems much more important than frivolity. We are all dispersed now and socialization is much less organic. Even when you have friends in the same city, meshing lifestyles such that everyone can meet is a rigorous exercise.
Organic socialization seems like it can be very difficult to regain, but steps can be taken (aside from forming and living in a commune). This is but one of the wondrous reasons for the Pyrate Party.