My girlfriend left me for a whole year. It ripped me apart. for a week after she cut the chord, I didn't leave the house. And it still hurt for weeks after, but the pain does lessen as time goes by. (little things can always set you off when you're in that state, but for the most part, I began to heal.)
I took alot from the experience. And we stayed very very good friends. For months, I was interested only in being single and getting my life organized. Then last year, she told me she was going to see another person. I thought I was over her, but this caught me off guard. It hurt worse than the initial break-up.
So I figured, screw it. The only way I'm going to move on is if I find someone else too. And to be frank, I hadn't had sex in a while, and I was mostly just interested in putting my dick in someone. So I began talking to this other girl.
Bare in mind that my ex was my best friend, and I didn't want to lose that. I just wanted her in my life SOMEhow. So the whole time I'm trying to start something up with new girl, I'm still talking to my ex. I had no idea, but right away, she became extremely jealous. Her other guy didn't work out, and after one date she stopped seeing him. Eventually she called me and told me she wanted me back. We hooked up that night.
We have been together for six months now (again) and are still going strong.