Sheryl Sandberg’s Lean In can be read by women as a call to action, convincing them they are capable, competent—and needed as corporate leaders.

A few months ago, the social stratosphere was blowing up with a little love—and surprisingly, even more hate—toward Lean InSheryl Sandberg‘s new book about women in the workplace. Supporters hailed her honest portrayal of a stalled feminist movement and her disappointment about operating at an executive level and still seeing so few women around her.

Some reviewers called her out of touch with the average working woman and, with billions of dollars and endless resources at her disposal, questioned her right to dole out career and parenting advice to women who struggle to pay the mortgage and the daycare bill in the same month.

I am not the COO of a billion-dollar social media empire, but I am a woman, wife and mother trying to pave a path in the male-dominated marketing and advertising industry. So I ordered the book, expecting it to be full of corporate speak, complaints about the lack of caviar at private preschools, and irrelevant anecdotes about breaking the heel of Louboutins on the airstairs of Facebook’s private plane.

What I found, however, was a feminist manifesto, a call to action for women to truly believe they are capable, competent, and needed at the leadership level. Whether you’re a veteran brand manager, a director of marketing, or even an entry-level project coordinator, something in this book will speak to you. Here’s what spoke to me.

Do not be afraid to sit at the table.

Studies have shown that women tend to doubt the value of their contributions during meetings and group discussions. They are often afraid that if they speak out of turn or say the wrong thing, they will be discovered for what they really are—frauds who snuck their way to the top.

But guess what? You have earned your place at the table just as much as the man sitting next to you has. Don’t be afraid to pull up that chair and jump into the conversation.

Accept the fact that not everyone will like you.

At the end of Sheryl Sandberg’s first six months at Facebook, Mark Zuckerberg sat her down for her first formal review and told her that her desire to be liked by everyone would hold her back. When you want to change things, he said, you can’t please everyone.

This is also a valuable lesson for those in the marketing industry.

Women often have an inherent desire to be liked, to be a positive force in a working environment. But it’s not always easy.

Brand managers are working toward the success of million-dollar drugs, and countless jobs, futures, and even patients’ lives are riding on that success. Sometimes tough choices must be made. You must not be afraid to be the one to make those decisions, even if it means you may have disgruntled subordinates or hurt feelings to deal with. And if you are able to be fair and compassionate in your opinion, you will earn the respect of your colleagues along the way.

Cry at work if you really need to.

At times you’ve probably wanted (if you haven’t already) to lock your office door in order to shed a few tears of frustration or to relieve stress. Passion and motivation drive us in our careers, and tears, like a good fit of cursing, can come from this passion.

Crying doesn’t make you any less of a professional.

If you feel the tears coming on, excuse yourself from the meeting and take a few minutes alone to calm down. And if someone knocks on the door to check on you, don’t be afraid to let the person in. Sometimes sharing strong emotions with professional partners can lead to deeper trust and a renewed sense of determination.

Bring your whole self to work.

We are brand managers, product directors, creative forces. But we are also women, and that can mean we are wives, mothers, daughters, sisters. And maybe we are also vibrant community activists, avid readers, accomplished athletes, or trained musicians.

As women we bring our outside roles and interests into the office—they give color and an extra dimension to our working lives. Maybe a discussion you had at a book club will influence the way you view a concept. Don’t be afraid to show and share those personal sides of yourself.

If possible, strive to find a company that lets you bring your whole self to work.

“Having it all” is a myth.

It’s true that the percentage of working women—even women out-earning their husbands—has risen dramatically over the past 30 years. But just because we’ve established ourselves permanently in the work force doesn’t mean we’ve gotten there without sacrifices.

Sometimes our hours in the office mean time away from family, friends and interests. Other times our kids can turn the house into a viral cesspool, and we may find ourselves working from home two weeks straight.

Research shows that women have trouble cutting themselves a break when they feel they’re not giving 100% to every role they lead. When they don’t measure up, they feel it’s a reflection of their failures.

But the truth is, having it all doesn’t mean doing everything perfectly. It means finding happiness and fulfillment in home, work and self—and accepting the ever-evolving balancing act that will get you there.

Don’t just fit in—speak out.

As a leader, you have an opportunity to set an example for all the women who will come after you.

How will you lead?

What will you teach them?

Celebrate the fact that you have worked your way up in a world still largely uninhabited by women—and start thinking about how you can bring other, worthy women to your level.