Understanding Guys: Is It Even Possible?!

I wish I could understand guys. One minute they can be so sweet, and the next, a pain in the rear. What is the cause for posting this? Well, let me tell you... So, we were at a church dance, and a group of friends and I went. While we were there, my girl friends and I had a contest going on. Whoever got asked to dance first, got to choose partners for the other two girls. What's so bad about that? The fact that WE had to ask THEM. It may not be a very big deal to some people, but for someone with social issues like me, it was TERRIFYING!! So I thought to myself, "Well, self, you aren't a total hideous monster. You have a shot at this at least." So I did all the right moves: I stood by myself, gave every guy that walked by that look (You know the one. The one that says hey-you're-cool-and-I-totally-wouldn't-mind-dancing-with-you-if-you-asked), had all my makeup done nicely...the whole sha-bang. Unfortunately, I wasn't asked first. So who did my friend to choose to dance with? The really funny guy that I just happened to know. It was made worse by the fact that he's about, oh, 6'2" and I'm a mere 5'1". So after my friend literally dragged me over to him, I was forced to ask him to dance, which btw was COMPLETELY embarrassing, we did a weird dance where we were in slow-dance position, but during a fast song, which means that we were moving side to side kind of fast, and with our height difference, I was JUMPING on my TIPPY TOES while he was practically dragging me around. Don't get me wrong, it was fun, but really embarrassing. But then it got even better... During the whole night, he kept saying "hi _my name_!" And basically actually acted like he noticed me, which btw no guys really pay attention to me a whole lot. Go figure. Added to the fact that everyone kept saying that he liked me, I, being the stupid naïve girl that I am, thought that he liked me too. See, here's the thing; I usually don't really like a guy unless 1)I think he likes me first, and 2) if I am actually attracted to him back. I don't mean to do it, it's just kind of the way I'm programed. So when he did all this stuff and everyone was making a big deal out of it, of course I fell. It only took about, oh, two days, to realize that he didn't really like me, and that he was just playing around. But I had already fallen. I thought about him a lot. It just wasn't healthy. So that's how I'm here now. I have mostly gotten over him, and I've sworn to my self that I won't like anyone again unless I know FOR SURE that they like me first. It's the only way to not get heart broken until you've actually loved. It may be lonelier this way, but I'm use to being alone. Man, I really wish I could understand guys.