Peter Bohler for TIME Strategy meeting Sandberg with LeanIn.org team members

Sheryl Sandberg’s first employees, according to her family, were her siblings David and Michelle. “Initially, as a 1-year-old and 3-year-old, we were worthless and weak,” they said in a toast at her wedding. But by elementary school the person who is currently the chief operating officer of Facebook, and arguably one of the most powerful women in America, had whipped them into shape, teaching them to follow her around the house and shout “Right!” after each of her orations. Was this a game? Sort of. “To the best of our knowledge Sheryl never actually played as a child,” they said. “[She] really just organized other children’s play.”

Sandberg tells these stories about herself early in her first book, a memoir–slash–”sort of feminist manifesto” in which she enjoins women to pursue their careers with more rigor, to engage more energetically in the corporate cook-off, to Lean In—as the book is titled—to the opportunities and challenges of becoming a boss. She says she had misgivings about sharing these family fables because they make her seem bossy, a term she takes issue with. “I notice bossy is applied almost always to little girls,” says Sandberg over lunch (she ordered a Wagyu hot dog with no bun and no relish). “It’s just not used for men.”

In person, Sandberg does not give the impression that she’s bossy. She gives the impression that she was born 43, that she was delivered preloaded with the capacity and will to order people around but also the capacity and will to ensure that they thrive. Now that she is really 43, she has so perfected these skills that merely helping run a $66 billion tech company is not quite enough of a challenge. So Sandberg has taken on a new mission: to change the balance of power. That quest and her plan of attack have brought out the broadsides.

(MORE: TIME’s Complete Coverage on Sheryl Sandberg)

It would be un-Sandbergian to write a book and just leave it at that. Her campaign comes with LeanIn.org, a nonprofit foundation with corporate partnerships, online seminars and guidelines for establishing support groups. It’s probably not an overstatement to say Sandberg is embarking on the most ambitious mission to reboot feminism and reframe discussions of gender since the launch of Ms. magazine in 1971.

The thing is, she’s in a pretty good position to pull it off. She’s the co-pilot of the biggest network of humans the world has ever seen: Facebook’s roughly 1 billion members, most of whom are female, at least in the U.S. She’s worth hundreds of millions of dollars. And she has an undeniable record of knowing how to get things done. Her résumé, with its by-the-book stints at Harvard Business School, McKinsey and the Treasury Department, does not reek of revolutionary, but in the lineage of key feminist figures, she may well turn out to be pivotal. “In a sense it’s almost like Betty Friedan 50 years ago,” says author and historian Stephanie Coontz. “She’s talking to a particular audience, but they really need this message.”

(MORE: Sandberg Exclusive Excerpt: ‘Why I Want Women to Lean In’)

Midflight Stall

Why, almost exactly 44 years after Lorena Weeks became the first woman to use the Civil Rights Act to win the right to be promoted, at Southern Bell, are we still arguing about women and success? Only flat-earthers and small boys don’t believe that women can lead huge Western democracies (thanks, Margaret Thatcher), head companies (thanks, Indra Nooyi), play exciting sports (thanks, Billie Jean King), rise to the rank of four-star general (thanks, Ann Dunwoody), change the world, trade cattle futures and be funny (thanks for all three, Hillary Clinton).

But women’s journey to the top is having an altitude problem. Young female executives begin on the same career staircase as men, but it’s almost as if the stairs change direction, Hogwarts-like, and take them somewhere else. For three decades, more women than men have graduated from college, but that academic dominance has not led to corresponding business or political success. There are currently only 17 heads of state out of 195 who do not have a Y chromosome. Women hold about 20% of all seats in parliaments globally. Slightly more than 4% of Fortune 500 companies are headed by women, and women hold 17% of board seats. Worse, these numbers aren’t changing very fast. Ten years ago, 14% of board seats were held by women. A decade has passed, and women have gotten a few inches farther into the boardroom. “Women are not making it to the top of any profession in the world,” says Sandberg. “But when I say the blunt truth is that men run the world, people say, ‘Really?’ That, to me, is the problem.”

Few people disagree that somewhere on the climb between the graduation podium and the C-suite, women are getting lost. The contentious issue is what—or who—is keeping them down. Fingers are pointed in every direction: the U.S. has primitive maternity-leave laws on par with those of Papua New Guinea—a country that still has actual cannibals. Women are hitting their childbearing deadlines around the time future executives are being winnowed out from regular management. Turnover at corporate boards, which are heavily male-dominated, is very slow; most have a mandatory retirement age of 72. American companies structure their workers’ days around the expectation that someone else is handling the home front. Men have welcomed women into the workplace, but housework, cooking and child-rearing duties are still borne largely by women.

(MORE: Forget About Mentors — Women Need Sponsors)