Guess I'll go Eat Worms

I consider myself to be a pretty likable person. I have a lot of friends, am friendly to most people, and feel as though I am generally respected and cared for. So, when I feel like someone doesn't like me, I feel threatened. And my feelings of being threatened turn into one of two things- hatred or confusion. Well, hatred is a pretty strong word. Let's say strong dislike or confusion.
In this case, confusion.
I have a co-worker who is naturally pretty shy. He doesn't say much, keep to himself for the most part, and quietly (VERY quietly) does his work. That's all fine. I started working here around the same time as this gent, so we were going through the new employment process together. I would try to ask him questions in the get-to-know-ya fashion, and he gave me a minimal response. But he was that way with everyone else too, so I didn't take it personally. As the months went on, I noticed more interaction with my other co-workers on his part. He had/has daily conversations with some of the other ladies, shares things with them, but has not included me in any of this. I must admit, I basically stopped trying to talk to him when all I got was a "hey" as a greeting. So now I'm not sure what to think- does he dislike me? Or does he think I'm sooooo different from him that we couldn't possibly have anything to talk about?
Normally, I wouldn't really care. And it's not like it's keeping me up at night. But I hate that feeling of awkwardness at work...when we are the only 2 people around. The silence is deafening. I kind of feel like I'm back in high school...sharing a lab table in Physics with Joey Jordan and Aaron Weaver.