Saw "Ghosts of Girlfriends Past" with a friend.  The main character is pretty much my personal jerk.  Although most girls would have discovered hope, I see quite the opposite--statistically a jerk will date many girls before he decides to settle down, so you are far more likely to be one of the many rather than "the one".  A persistent patten of behavior is usually so deeply ingrained that it would be unrealistic to expect drastic changes over night.  In the end, the work/patience is probably not worth it given the odds.

But Hollywood knows that audiences enjoy feel-good movies...so go ahead and feel good about your unhealthy, soul-strangulating relationships, ladies!

Maybe this is all karma at work.  I wasn't the nicest person to several of the men I dated.  I wasn't cruel, but I was thoughtless and selfish.  For some reason, the worse I behaved, the more they liked me.  I canceled dates at the last minute, routinely showed up late, changed plans without asking other people...basically lived on a whim.  And now I'm realizing how much it sucks to be on the other end.

I think I finally understand why they put up with all my crap.  We are all on our best behavior at the beginning of any relationship, which sets our partners up for failure.  Once we start behaving poorly, our partners begin to wonder what happened and how they can get us to act the way we used to.  Of course, their efforts are wasted (if not counterproductive) and they're left unhappy and hurting.  Now that the shoe's on the other foot, I'm regretting the way I have treated my boyfriends in the past.

Words of C.S. Lewis that most people can relate to at least to some degree:

All this is flashy rhetoric about loving you.
I never had a selfless thought since I was born.
I am mercenary and self-seeking through and through;
I want God, you, all friends, merely to serve my turn.

Peace, reassurance, pleasure, are the goals I seek,
I cannot crawl one inch outside my proper skin;
I talk of love -- a scholar's parrot may talk Greek --
But, self-imprisoned, always end where I begin.

It's not to say that we don't care of our friends, but everything eventually comes back to "me".