Sheryl Sandberg has burst into tears in the office, more than once. She has failed at such crucial Mommy Tasks as remembering to dress her son in a green shirt for St. Patrick’s Day — inwardly seething at the officious super-mommy who chided her sartorial shortcomings and worrying, I’m a bad mom.

Sandberg spent her college years – her Phi Beta Kappa at Harvard college years – constantly feeling “like I was about to get caught for not really knowing anything.”

In short, the chief operating officer of Facebook is human in a – watch me get into trouble here – distinctively female way: emotional, guilt-ridden and plagued by a chronic, if low-grade, case of impostor syndrome. She is also fabulously smart, successful and wealthy.

Which is why Sandberg’s candid new book, “Lean In: Women, Work and the Will to Lead,” marks a valuable contribution to the endless debate over gender, motherhood and work, and why her risky disclosures are so important.

The takeaway, especially for younger women, is: If Sheryl Sandberg can feel this way and still be Sheryl Sandberg, maybe I can too.

It is also why some of the snarky early reaction to Sandberg’s book has been so surprising, reminiscent of a junior high school clique whose leader has passed a note, Let’s all be mean to Sheryl today.

Yes, when Sandberg finds lice in her children’s hair, the family is on board the eBay corporate jet. She writes, as she concedes, from an especially privileged perch. Most pregnant women lumbering to work from a distant parking spot don’t have the clout to tell the company’s founders that they must add premium spaces for expectant mothers, stat.

But this is precisely the point. Sandberg could have chosen not to make feminism her signature issue. Indeed, when Sandberg gave a widely viewed talk on the dearth of women leaders, friends and colleagues warned she would “harm my career by instantly typecasting me as a female COO and not a real business executive.”

The contrast with Yahoo CEO Marissa Mayer, Sandberg’s former Google colleague, is striking. “I don’t think that I would consider myself a feminist,” Mayer told PBS for its “Makers” documentary. “I proudly call myself a feminist,” Sandberg writes.

Mayer proclaims that her new baby has “been way easier than everyone made it out to be.” Sandberg reveals that “I still struggle with the trade-offs between work and home on a daily basis.”

Mayer decreed that Yahoo employees could not work from home. Sandberg dismisses “judging employees by face time rather than results.”

Early on, to leave by 5:30 to have dinner with her children, Sandberg sneaked to her car when no one was looking. Now, she has gone public with her heretical (by Silicon Valley standards) schedule.

Sandberg’s book is laced with caveats: Yes, many women don’t have the luxury of choosing between work and family. Yes, many women with that luxury choose home over work, and that’s fine too.

Sandberg prods women to consider how their own attitudes and behavior unwittingly exacerbate the problem. “We hold ourselves back in ways both big and small,” she writes. “We lower our expectations of what we can achieve.”

Her advice is obvious yet hard to execute. Sit at the table: Believe – or act like you believe – you have something valuable to say. Don’t leave before you leave, tailoring your ambitions (and constraining future choices) because you fear, down the road, that you will be unable or unwilling to juggle the load.

This is not blaming the victim. It is empowering her.

At the same time, women must learn to navigate the paradox of success and likability: Men viewed as competent and successful are admired for it; women with the same attributes are liked less.

Sandberg’s book was conceived before Anne-Marie Slaughter’s Atlantic piece, “Why Women Still Can’t Have It All.” But it serves as a useful rebuttal to Slaughter’s depressing, and potentially self-fulfilling, message.

“The world has not evolved nearly as much as I believed it would,” Sandberg writes, noting the number of women in her Harvard Business School class who have dropped out of the work force.

Evolution, by definition, is painfully slow. “Lean In” offers a roadmap for accelerating it.

Ruth Marcus is a columnist for The Washington Post. She can be contacted at ruthmarcus@washpost.com