Funny how the OP was banned for obsessing over a prossie. Says it all really and pretty much sums up my thoughts on this kind of topic.
Don't get me wrong though, of course there are a few prossies I would have liked to shag but they retired before I got around to them. But, I just view it like, prossies come and go all the time, that's just the nature of prossies. Can't expect them to wait around forever specifically for me to get around to arranging to fuck them.
Saying that though, of those I really wanted to fuck it is only really a few I missed out on. I tended to have a bit of a habit of luckily managing to fuck the ones I really wanted to see just before they retired. I guess, the point being for me, is if very interested in fucking a particularly prossie, then get in there whilst the chance is still there. Seize the day and all that.
But, yeah, it's a moderate source of annoyance in this punting hobby, but certainly not something that "will haunt me forever"
One of the great things about this pursuit is that there is always some new hot young thing around the corner. The quality, value and quantity can vary of course. But always better to look forwards rather than back IMHO.