Million of sperms die during intercourse, sperms die after 3 months if unused, 1/3 of all male and female sperms joined together die. Millions of unusable sperms go to waste because they are simply rejects as sperms. You succeeded not because you are the fittest but because of nature’s lottery. If you’re lucky and have no birth defect you still have to contend with life especially if you are poor and sickly. But in the end you still grow old and die.

Just sheer bad luck.

If your fishing for predestination, personally I see no evidence for that. The sperm that created all of us was simply first. I think I might have cheated to win but I’m not sure, it’s hard to remember back that far.

"head" start..

Who cares, if it hadn't been that sperm it might have been another or none at all, if that had been the case I would not be here to worry about it, so why worry about it now?
If my dad had or had not had a wank earlier that day, I would not be here, neither would I be if he had crashed his car, or if my Mum had run off with the milk man... the variables are infinite, but things turned out how they are and I'm sort of glad they did.

Half of me. Not understanding that "why" has nothing to do with how life works, is a fundamental element of religious beliefs.

Why not? One had to win.