What starts out as a near 50-50 professional split among new lawyers, for example, becomes a big gap: Women are just 17 percent of equity partners at law firms generally, according to the National Association of Women Lawyers.

When women have children, they’re penalized: They’re considered less competent, they’re less likely to be hired for a new job and they’re paid less. For men, having a child helps in hiring and pay. For many families, it starts to “just make sense” for the husband to take on the role of primary breadwinner while the wife drops out of the labor force, compromising future earnings when she tries to go back to work.

“You realize how many women are left standing as you age, and what happens to your brilliant and talented friends and colleagues from your 20s and 30s,” said Heather Boushey, the executive director and chief economist for the Washington Center for Equitable Growth, who has provided advice to the Clinton campaign. “These are tough lessons, and ones that you may not think are as pressing until you actually see them happen to your own friends and cohorts.”

Even for women active in feminist causes in college, as I was a dozen years ago, that can be a rude awakening. As a young lawyer, one of the first things I noticed about department meetings at my law firm was not just the dearth of female partners, but that one of the few female partners always seemed to be in charge of ordering lunch. I listened as some of my male colleagues opined on the need to marry a woman who would stay home with the children — that wasn’t sexist, they insisted, because it wasn’t that they thought only women should stay home; it was just that somebody had to, and the years in which they planned on having children would be crucial ones for their own careers.

I saw that the older white, male partners who mentored the younger white, male associates were able to work long days and excel professionally precisely because their stay-at-home wives took care of everything else; I saw that virtually none of the female partners had a similar setup.

In jobs that followed, managers would remark that they wanted “more women” and proceed to reject qualified candidates. (Similar dynamics took place with minority candidates.) There were always reasons — not the right cultural fit, not the right experience, a phenomenon of unintentional sexism now well documented in controlled studies. I watched as men with little or irrelevant experience were hired and promoted, because they had such great ideas, or they fit in better. “We want a woman,” the conclusion seemed to be, “just not this woman.”

Watching a primary election in which an eminently qualified woman long assumed to be a shoo-in for the Democratic nomination faces a serious challenge from an older white guy with exciting ideas, many women my age and older hear something familiar, and personal, in the now-common refrain about Hillary Clinton: “I want a woman president, just not this woman president.”