OP should have titled the thread "why you are alone" to fully bring his point across.
Even if one is lucky enough to be at the right place, at the right time to meet the significant other, it's not enough, both have to also be ready and willing to make a serious relationship/marriage work. When my longest and most promising relationship ended, I thought I hit rock bottom but as time went by, it turned out to be a blessing in disguise. I know so many good people whose lives got very difficult with divorces and having kids with now estranged partners.
I'm probably alone on this but I would rather not have kids if I cannot provide for them as I want than just have a kid and "hope" I can give them the life they should have. When I was growing up there were way less things a kid "needed" to have a "normal" childhood.
Now 38, I don't have the will power needed to make things work, the stuff I never sweat before bothers me now. Last time I had a woman over, I was pissed when I saw her hairs in the shower drain. Stuff like that didn't bother me in my 20's and early 30's.
My libido is now starting to decline but the most concerning thing is that I am ok with masturbating as a permanent replacement for women. Not sure exactly which disorder I'm developing but I keep justifying it as a better, hassle free solution rather than dealing with all the risks involved with pursuing women. I had lots of fun when I was younger, now I view courting/dating as an inconvenience.
Another disturbing trend I notice is that I like toying with women now, flirt til I get them interested and then disappear or turn coldblooded once I sense that I could have them. It's like a power trip, removing the only constant in the man vs. women game aka the desire to get laid, drives them crazy.
Before you suggest seeking professional help, really, fapping in the shower to the memory a random hookup in the past completely removes the need for a woman in my life now.