I've heard that this is common for our type, and it's definitely one of my problems as well.
I believe that the reason that I feel like this, is because I only get along well with very few people, and when I watch the others in the crowd getting along perfectly, I feel like I'm missing out. For example, I'm having a hard time saying goodbye to people after an event if they aren't someone I get along with - even if I know them decently. It seems like that they don't think I care. Even if I do say goodbye, it's more of an act of them being nice than an actually personal thing.
This is a pretty influental problem of mine, and it's one of the main things that bring me down. I certainly believe that quality > quantity in terms of friends, but it's hard for me to keep this mindset when I want to get along more people and I can't.
How do you guys handle this?