Girl problems, Guy talk, guys only. Anyone with similar prob is welcome.?

[Barney]

I'm just going to give the skinny, not too many details. I knew this girl for most of my life, about 18 years or so, we're 20 now. Basically, before I had any experience with women, she had a huge thing for me. We're we're great friends and I actually had a thing for her too. But that was before I knew what I was supposed to do. Skip ahead just near the end of last semester of college, we got in a big over Facebook. Now we don't talk. My life doesn't have a whole lot going on right now but I'm not huddled up in my room. I don't think about it as much as I used to and in fact am glad I don't deal with her anymore. But every now and then I think about it and then that's it. Some times though I can't shake it. My question is what I can do to completely drop it. Any ideas or advice from past experiences are welcome. I don't have any pics, items or anything tying me to the past. I do in fact have a life. I take martial arts, I hit the club, I hang with bros, im getting numbers from other girls, I'm starting next semester soon but for some reason it just isn't cutting it. Any ideas on possible reasons? I keep thinking like I did something wrong or offended her or something like I'm in some kind of guilt trip. Well not really anymore but still. I keep thinking I f***** up. Can someone give me an outside perspective? Guys only.