just turned 32 and I feel this as well. I feel into a deep depression shortly after graduating for this exact reason; mourning the loss of that regular contact with similar-age, similar-interest people as they all moved across the country to start their careers. Similar thing happened a few years later when I was internally transferred to another group at work with no people my age. It's never been the same since.

I've always scoffed at paying for those "activity groups" (what kind of loser would pay for friends?), but recently I've started reconsidering.