I have recently encountered people who break up with the people that they date for good or not so good reason and then get fed up when those poor (or most often actually, extremely lucky) people don't pine for them forever! They want to be "The one that got away".
Um, there is no such thing. Generally if you dump someone and expect them to pine for you, they really are better off, no matter how wonderful you consider yourself to be. A person who delights at the pain and sadness of another is merely a liability; A lump of coal to be swept out of the path and forgotten as you move on to your diamond.
It is most often that when these poor sods wake up and realise what a favour the dumper did them, they feel that overwhelming sense of relief and freedom and move on without looking back and it is the person who is fed up at not being hung-up on who is left actually being hung up on a long-forgotten moment. It is a sad, sad thing and a degree of narcissism that can't be considered healthy or normal.
Should any friendship ensue afterward, it is usually because the person who was dumped has moved on to such a degree that the dumper has absolutely no effect on them whatsoever. Sadly this is often misunderstood by the dumper as them still having some effect on the now very happy dumpee and perhaps reignites the ludicrous notion that they were, in fact, "the one that got away". It is rather amusing on some level and just absolutely astounding at the level of absolute ignorance that these Dumpers have as they really just don't get it.
To spell it out for the men and women out there who actually think that their ex is crying into their pillow at night for them or secretly kicks themselves for having "let you get away", wake up, you are not missed, not pined for and that person is most certainly better off as you turned out to be a bad, bad person. Now let it go and move on, dammit!