Why are teenage guys so desperate for a girlfriend?

I see some kids I know and it's pathetic. They are so desperate for a girlfriend I can't stand it. I see them sucking up to any girl, trying to get her but like usual ending up in the friend zone haha. I read their posts on Facebook and I can just tell they want a girl soooo badly. I don't care if a guy wants a girl I mean I do, but I don't lower my standards and try to get with ANY girl. I'm not that pathetic. Why do guys my age do it? I'm 18, and I've never had a girlfriend, but I would rather be single than be another loser who is crying out for a girl. It really bothers me when guys I know do this haha. So does anyone know why they do it? Thanks.