My girlfriend and I are acquainted with no fewer than two-dozen forty-something women, all of them successful, well-educated, charming ladies. They are librarians, museum curators, teachers and the like. Besides these similarities, they hold two more characteristics in common. They are all single and childless.

Any of these women would have made fine partners and wonderful mothers. They could have borne bright, responsible, successful children who could have contributed greatly to society. But for various reasons it wasn’t to be.

Most spent their twenties working on themselves, attending graduate school and later focusing on their careers. By their thirties, they found themselves in long-term relationships that ended after a half dozen or so years. Their stories are strikingly familiar. Our friend and her partner moved in together. Years passed, until one day he (or she) decided it wasn’t working for him anymore. It took five to ten years to realize this, sure, but better to recognize it now than to make the mistake of getting married. He packed his things and by lunch he was out of her life forever.

Now, at forty, our friend finds herself alone, wondering where the time went. It seems like only yesterday she was a freewheeling twenty-something with nothing but time. She is now in full panic mode. Her biological clock is about wound down. As if to illustrate her desperation, she goes in for speed dating, but there are slim pickings for a forty-something woman. She is introduced to a forty-six-year-old divorced real estate agent and something about him rubs her the wrong way. Maybe his cocky attitude, which seems absurdly out of place at speed-dating night in the dingy basement of St. Ambrose Church. But even now she cannot help being picky.

She goes on this way for a few more years, then, with a sigh, accepts that her childbearing years are behind her. She settles into her spinsterhood and adopts another dog.

ALL OF THESE women desperately want a husband and children, but most are deeply afraid of marriage having grown up in an era when nearly half of all marriages end in divorce. Most come from divorced families themselves, and as a consequence put marriage off as long as possible. But life passes quickly. For middle class women, the window for children is a narrow one lasting no more than twenty years. If she spends half of those years cohabiting and that relationship comes to naught — for few educated, middle class women copy their lower class sisters in bearing children out-of-wedlock — she has thrown away her chance.

If these women are sad or depressed at missing out on motherhood, they hide it well. Most have bought homes (statistics show that single women buy far more homes than single men), they have good jobs, they are involved in their churches and communities, and they live active social lives, and not just online. There are exceptions. One of our friends, a single 41-year-old Ivy League graduate, could not take the gray winters here in St. Louis and recently picked up and moved to Austin, Texas, hoping to start over yet again. She finally found a way to make the rest of us envious of her.

MEANWHILE, IN OUR inner-city neighborhood, there are countless poor, young, single mothers with more children than they can handle. If, as evolutionary biologists believe, the purpose of life is simply to pass on one’s genes, they are Darwinian superstars. One neighbor started having kids at fourteen. She is now 26 and on her ninth child, and probably will continue to have kids until Mother Nature in the guise of menopause mercifully cuts off her supply line.

It is hard to imagine that few if any of these children will be successful. They attend (sporadically) the worst schools in the world. They have no decent male role models. You will not find a single book in their homes, only the constant din of the television set. For the African-Americans among them, they are taught that being successful is “acting white.” Sad, but in all likelihood, they will end up just like their parents: single mothers with too many children, forced to work two minimum wage jobs and still unable to make ends meet, or, worse, like their irresponsible, absentee fathers.

What’s missing is a sense of balance. My accomplished friends seem to have traded children for success, while my ill-fated neighbors seem to have traded children for failure. As those of us who are parents — and neither great successes nor great failures — know, it was a bargain you never had to make.