Finding the "One"

I sit and wonder so often if there really is someone out there for everyone. In all honesty, my attitude is one of a more cynical nature. I just can't seem to believe that there is someone for everyone. There must be those people who are just meant to be alone and walk through their life without someone else by their side. And in no way am I saying that that is necessarily a bad thing. I don't mind being by myself most days - in fact I would rather be alone then be with someone I don't get along with, feel comfortable around, or have enjoy common interests with

I had a conversation with someone rather recently and they were mentioning another friend and how in her entire life she had never been single for more than a couple months. "Sad" was the word that was used to describe that girl. But what word describes someone who can't make relationships last longer than that amount of time?

Sometimes I wonder if there's some part of me that does not work in relationships. Maybe I try too hard, maybe I don't try enough, maybe I'm looking too hard, maybe I'm not looking at all, maybe I trust people too much, maybe I don't trust enough.....It seems like most people have one of those catch phrases ready at any time to solve the 'single problems' of their friends.