Single men, why is it so hard to get a girlfriend?

I don't know what's wrong with me. I work out regularly, I'm tall enough. I have a good job and I'm kind of funny. I'm pretty cool, by the books.<br><br>But I've still never had a girlfriend. I'm 27 years old now and the loneliness is killing me.<br><br>I try to date. I get rejected every single time. I've worked with heaps of girls and I've tried to pursue a relationship with some of them but they've never been interested. <br><br>I'm pretty socially isolated already. What's wrong with me?