lol uncle pony those were exactly the reasons I was thinking.
This happened to me actually, before I realized how it all works. Still was insecure and didn't know that girls will "save themselves" for later when they meet a guy they want to date as not to seem "slutty". Absolutely ridiculous and twisted in my opinion, but I guess that's just the way the world spins.
Thought process in my head went sorta like this:
Met a really great girl at school, while studying for a test. Saw her again at a bar that weekend, and hit it off with her. Spent a lot of time together, and there was chemistry between us. She invited me back to her house- there's only one reason for that. Except we only played around... what's wrong with me? She just wanted to fool around, then send me on my way. I guess i'm not the kind of guy she really wants, and i'd rather not have the akward "friends" speech on the phone. *crumple number, throw in trash*
Anyways maybe this crummy story might give ya some insight.

Or not, it's pretty difficult to get the jist of a situation from a message on a forum.