Marissa Mayer is naïve. Or so say a million mommy blogs, and I just can’t get this issue out of my head. Once the baby is born, say the blogs, she will see that a two-week maternity leave is not realistic. This is a typical gender war: women judging each other is one of the key mechanisms for the delivery of gender bias.

Mind you, I didn’t take a two-week maternity leave. And I was horrified when I heard, in my twenties, of a law-firm partner who said, when a lawyer in his firm took only two weeks, “Now, that’s the responsible way to have a baby.” But that was me, in my particular situation.

But let’s consider a hypothetical woman, Suzie Brilliant. Say she’s a high-level, but not C-suite, executive who has led teams that have produced products so influential they have changed Americans’ daily lives. Say she’s stalled out just below the C-suite, for whatever reason. Say she’s approached by a major company and offered the CEO job with a package of up to $59 million for her first year. Boy, will this put her back in the limelight. If the company fails – and many think it will: Suzy’s the fifth CEO in a short order because the company’s up a creek competitively – she’ll still be CEO material. If it succeeds, she will be mega.

So she goes for it. Sure, she will miss the experience most women have, and cherish, upon the birth of her first child, which she regrets; but a public company in crisis would be highly unlikely to hire a CEO who says she will be gone for three months after her first three months on the job. But she also promises herself she will make up for it later. By the time the child is three, she promises herself, she will step back, with her $59 million, and reassess her options. Or else the company will go bust in short order, and she will take a well-earned break.

Now, I have no inside knowledge, ladies. But neither do you. What would you do if you were Suzie Brilliant? After I had kids, I came home religiously at 5:30 virtually every night for fifteen years. But I tell you what I would do if I were Suzie Brilliant. I would take the opportunity, and the $59 million.

Why do women fight about this? First we define the ideal worker to be inconsistent with motherhood. This means that women who live up to our ideals of motherhood often feel inadequate and vulnerable because they fear they are losers who never lived up to their potential. And it means that women who live up to our ideals at work often feel inadequate and vulnerable because they fear they are bad mothers who didn’t spend enough time with their children. And then each group judges the other.

This happens all the time. Typically (although not always), it’s a gen(d)erational conflict. Older women look at younger women who want to take a career break or go part time and say, “They just don’t understand what it takes to succeed in this business.” And the younger women respond, “We don’t your sorry-ass lives. You just turned into men, that’s what you did.”

Why are these fights so heartfelt? It’s a classic Difficult Conversation because each side’s identity is at risk. The older women, worried that they didn’t spend enough time with their children, feel the need to insist that they did: “I worked full time straight through and my children turned out great.” The younger women feel that they older women are telling them they are losers unless they abandon their ideals of motherhood.

You will notice men don’t fight about this. That’s because the ideal father traditionally has been defined in a way that makes it possible to be both an ideal worker and ideal father.  So women struggle but men traditionally haven’t, because women, but not men, feel caught between two social ideals that are cherished, central to our identities, and inconsistent. Fair? Nope.

Let’s respond by working to change our social ideals not by turning on each other.  None of our solutions is perfect, because the situation does not allow for perfection. Luckily, perfection is not required. Insisting on perfection, in childrearing and in life, is a path to neurosis.

Children need love, stability, and guidance. There are many ways to accomplish this. Tolstoy was wrong. Happy families aren’t all alike.