I've had a life long struggle with trying to make friends. I notice that for some people, friendships come easily. For me, however, it's been a huge struggle, an almost overwhelming one.
I look at facebook and see people I knew in college that I would have liked to get to know better, but they would always put distance there. They already had their established cliques or best friends. I didn't know how to get into it. I'd try and it wouldn't work. Actually the harder it seems you try, the worse people will treat you because then you look desperate. So I stopped and just let it be.
Now that I'm much older I've decided to let go of this. It's okay not to have lots of friends. It's even okay to not have any friends at all, just family members or pets. This is how I've come to terms with it and tried to make peace with it.