The heartache of ending a relationship is a hugely complicated thing. I can't begin to imagine the pain of being dumped (thankfully I haven't had to experience that yet) but I do know that it's rarely a walk in the park for the one making that decision either. Just because you end a relationship it does not mean the feelings go away. And I also know a lot of people who are unhappy in their relationship but too frightened to take the leap.
I have been through 3.5 break-ups in my life. The first, when I was 16, happened over MSN chat; it was a calm, mutual agreement in which I told my boyfriend I'd seen Sammie K wearing his hoodie and that he hadn't texted me for 2 days. He suggested it wasn't working and I full-heartedly agreed. But I still felt a bit sad and "bleurgh" for about a week. Just as he had been my first forray into love, he was then my first into heart-break. I had no idea...
The second is the 0.5 in this break up equation. We only dated for about 6 weeks and I wasn't really aware it was even a relationship until in week 4 he confessed undying love (which I gently told him wasn't reciprocated). By week 5 he was clingy as hell and when I learned he'd asked his last girlfriend to marry him I broke it off in week 6. The resulting tantrum is what qualifies this non-relationship for break-up status: threats of suicide (that I did not believe for a second), full-on screams of anguish and a really quite unnerving ambush when I was home alone two days later. What I took away from this was don't date drummers, because they must clearly ALL be unhinged (a sweeping statement, but it would prove not to be untrue 5 years later).
At the end of that school year my cute, geeky friend that I set next to in Media Studies bought me chocolate and asked me to prom on one knee. I was a bit surprised but totally smitten. I finally gave up my closely guarded virginity (on prom night) and fell in love in a crazed endorphin and hormone tornado. We did not argue until our 1 year anniversary, when he was a grumpy asshole and made me cry for the first time. But you can't break up on your 1 year anniversary! So we made up and carried on.