I got pregnant with my first child in the summer of 2004. At the time, I was running the online sales and operations groups at Google. I had joined the company three and a half years earlier when it was an obscure start-up with a few hundred employees in a run-down office building. By my first trimester, Google had grown into a company of thousands and moved into a multibuilding campus. My pregnancy was not easy. The typical morning sickness that often accompanies the first trimester affected me every day for nine long months. I gained almost seventy pounds, and my feet swelled two entire shoe sizes, turning into odd-shaped lumps I could see only when they were propped up on a coffee table. A particularly sensitive Google engineer announced that “Project Whale” was named after me. One day, after a rough morning spent staring at the bottom of the toilet, I had to rush to make an important client meeting. Google was growing so quickly that parking was an ongoing problem, and the only spot I could find was quite far away. I sprinted across the parking lot, which in reality meant lumbering a bit more quickly than my absurdly slow pregnancy crawl. This only made my nausea worse, and I arrived at the meeting praying that a sales pitch was the only thing that would come out of my mouth. That night, I recounted these troubles to my husband, Dave. He pointed out that Yahoo, where he worked at the time, had designated parking for expectant mothers at the front of each building. The next day, I marched in - or more like waddled in - to see Google founders Larry Page and Sergey Brin in their office, which was really just a large room with toys and gadgets strewn all over the floor. I found Sergey in a yoga position in the corner and announced that we needed pregnancy parking, preferably sooner rather than later. He looked up at me and agreed immediately, noting that he had never thought about it before. To this day, I'm embarra**ed that I didn't realize that pregnant women needed reserved parking until I experienced my own aching feet. As one of Google's most senior women, didn't I have a special responsibility to think of this? But like Sergey, it had never occurred to me. The other pregnant women must have suffered in silence, not wanting to ask for special treatment. Or maybe they lacked the confidence or seniority to demand that the problem be fixed. Having one pregnant woman at the top-even one who looked like a whale-made the difference. Today in the United States and the developed world, women are better off than ever. We stand on the shoulders of the women who came before us, women who had to fight for the rights that we now take for granted. In 1947, Anita Summers, the mother of my longtime mentor Larry Summers, was hired as an economist by the Standard Oil Company. When she accepted the job, her new boss said to her, “I am so glad to have you. I figure I am getting the same brains for less money.” Her reaction to this was to feel flattered. It was a huge compliment to be told that she had the same brains as a man. It would have been unthinkable for her to ask for equal compensation. We feel even more grateful when we compare our lives to those of other women around the world. There are still countries that deny women basic civil rights. Worldwide, about 4.4 million women and girls are trapped in the s** trade. In places like Afghanistan and Sudan, girls receive little or no education, wives are treated as the property of their husbands and women who are raped are routinely case out of their homes for disgracing their families. Some rape victims are even sent to jail for committing a “moral crime.” We are centuries ahead of the unacceptable treatment of women in these countries. But knowing that things could be worse should not stop us from trying to make them better. When the suffragettes marched in the streets, they envisioned a world where men and women would be truly equal. A century later, we are still squinting, trying to bring that vision into focus. The blunt truth is that men still run the world. Of the 195 independent countries in the world, only 17 are led by women. Women hold just 20 percent of seats in parliaments globally. In the United States, where we pride ourselves on liberty and justice for all, the gender division of leadership roles is not much better. Women became 50 percent of the college graduates in the United States in the early 1980s. Since then, women have slowly and steadily advanced, earning more and more of the college degrees, taking more of the entry-level jobs, and entering more fields previously dominated by men. Despite these gains, the percentage of women at the top of corporate America has barely budged over the past decade. A meager twenty-one of the Fortune 500 CEOs are women. Women hold about 14 percent of executive officer positions, 17 percent of board seats, and constitute 18 percent of our elected congressional officials. The gap is even worse for women of color, who hold just 4 percent of top corporate jobs, 3 percent of board seats, and 5 percent of congressional seats. While women continue to outpace men in educational achievement, we have ceased making real progress at the top of any industry. This means that when it comes to making the decisions that most affect our world, women's voices are not heard equally. Progress remains equally sluggish when it comes to compensation. In 1970, American women were paid 59 cents for every dollar their male counterparts made. By 2010, women had protested, fought, and worked their bu*ts off to raise that compensation to 77 cents for every dollar men made. As activist Marlo Thomas wryly joked on Equal Pay Day 2011, “Forty years and eighteen cents. A dozen eggs have gone up ten times that amount.” I have watched these disheartening events from a front-row seat. I graduated from college in 1991 and from business school in 1995. In each entry-level job after graduation, my colleagues were a balanced mix of male and female. I saw that the senior leaders were almost entirely male, but I thought that was due to historical discrimination against women. The proverbial gla** ceiling had been cracked in almost every industry, and I believed that it was just a matter of time until my generation took our fair share of the leadership roles. But with each pa**ing year, fewer and fewer of my colleagues were women. More and more often, I was the only woman in the room. Being the sole woman has resulted in some awkward yet revealing situations. Two years after I joined Facebook as chief operating officer, our chief financial officer departed suddenly, and I had to step in to complete a funding round. Since I had spent my career in operations, not finance, the process of raising capital was new and a bit scary. My team and I flew to New York for the initial pitch to private equity firms. Out first meeting was held in the kind of corporate office featured in movies, complete with a sprawling view of Manhattan. I offered an overview of our business and answered questions. So far so good. Then someone suggested that we break for a few minutes. I turned to the senior partner and asked where the women's restroom was. He stared at me blankly. My question had completely stumped him. I asked, “How long have you been in this office?” And he said, “Oh year.” “Am I the only woman to have pitched a deal here in an entire year?” “I think so,” he said, adding, “or maybe you're the only one who had to use the bathroom.” It has been more than two decades since I entered the workforce, but so much is still the same. It is time to face the fact that our revolution has stalled. The promise of equality is not the same as true equality. A truly equal world would be one where women ran half our countries and companies and men ran half our homes. I believe that this would be a better world. The laws of economics and many studies of diversity tell us that if we tapped the entire pool of human resources and talent, our collective performance would improve. Legendary investor Warren Buffett has stated generously that one of the reasons for his great success was that he was competing with only half of the population. The Warren Buffetts of my generation are still largely enjoying this advantage. When more people get in the race, more records will be broken. And the achievements will extend beyond those individuals to benefit us all. The night before Leymah Gbowee won the 2011 Nobel Peace Prize for helping to lead the women's protests that toppled Liberia's dictator, she was at a book party in my home. We were celebrating the publication of her autobiography, Mighty Be Our Powers, but it was a somber night. A guest asked her how American women could help those who experienced the horrors and ma** rapes of war in places like Liberia. Her response was four simple words: “More women in power.” Leymah and I could not have come from more different backgrounds, and yet we have both arrived at the same conclusion. Conditions for all women will improve when there are more women in leadership roles giving strong and powerful voice to their needs and concerns. This brings us to the obvious question-how? How are we going to take down the barriers that prevent more women from getting to the top? Women face real obstacles in the professional world, including blatant and subtle s**ist, discrimination, and s**ual hara**ment. Too few workplaces offer the flexibility and access to child care and parental leave that are necessary for pursuing a career while raising children. Men have an easier time finding the mentors and sponsors who are invaluable for career progression. Plus, women have to prove themselves to a far great extent than men do. And this is not just in our heads. A 2011 McKinsey report noted that men are promoted based on potential, while women are promoted based on past accomplishments. In addition to the external barriers erected by society, women are hindered by barriers that exist within ourselves. We hold ourselves back in ways both big and small, by lacking self-confidence, by not raising our hands, and by pulling back when we should be leaning in. We internalize the negative message we get throughout our lives-the messages that say it's wrong to be outspoken, aggressive, more powerful than men. We lower our own expectations of what we can achieve. We continue to do the majority of the housework and child care. We compromise our career goals to make room for partners and children who may not even exist yet. Compared to our male colleagues, fewer of us aspire to senior positions. This is not a list of things other women have done. I have made every mistake on this list. At times, I still do. My argument is that getting rid of these internal barriers is critical to gaining power. Others have argued that women can get to the top only when the institutional barriers are gone. This is the ultimate chicken-and-egg situation. The chicken: Women will tear down the external barriers once we achieve leadership roles. We will march into our bosses' offices and demand what we need, including pregnancy parking. Or better yet, we'll become bosses and make sure all women have what they need. The egg: We need to eliminate the external barriers to get women into those roles in the first place. Both sides are right. So rather than engage in philosophical arguments over which comes first, let's agree to wage battles on both fronts. They are equally important. I am encouraging women to address the chicken, but I fully support those who are focusing on the egg. Internal obstacles are rarely discussed and often underplayed. Throughout my life, I was told over and over about inequalities in the workplace and how hard it would be to have a career and a family. I rarely heard anything, however, about the ways I might hold myself back. These internal obstacles deserve a lot more attention, in part because they are under our own control. We can dismantle the hurdles in ourselves today. We can start at this very moment. I never thought I would write a book. I am not a scholar, a journalist, or a sociologist. But I decided to speak out after talking to hundreds of women, listening to their struggles, sharing my own, and realizing that the gains we have made are not enough and may even be slipping. The first chapter of this book lays out some of the complex challenges women face. Each subsequent chapter focuses on an adjustment or difference that we can make ourselves: increasing our self-confidence, getting our partners to do more at home, not holding ourselves to unattainable standards. I do not pretend to have prefect solutions to these deep and complicated issues. I rely on hard data, academic research, my own observations, and lessons I have learned along the way. This book is not a memoir, although I have included stories about my life. It is not a self-help book, although I truly hope it helps. It is not a feminist manifesto-okay, it is sort of a feminist manifesto, but on that I hope inspires men as much as it inspires women. Whatever this book is, I am writing it for any woman who wants to increase her chances of making it to the top of her field or pursue any goal vigorously. This includes women at all stages of their lives and careers, from those who are just starting out to those who are taking a break and may want to jump back in. I am also writing this any man who wants to understand what a woman-a colleague, wife, mother, or daughter-is up against so that he can do his part to build an equal world. This book makes the case for leaning in, for being ambitious in any pursuit. And while I believe that increasing the number of women in positions of power is a necessary element of true equality, I do not believe there is one definition of success or happiness. Not all women want careers. Not all women want children. Not all women want both. I would never advocate that we should all have the same objectives. Many people are not interested in acquiring power, not because they lack ambition, but because they are living their lives as they desire. Some of the most important contributions to our world are made by caring for one person at a time. We each have to chart our own unique course and define which goals fit our lives, values, and dreams. I am also acutely aware that the vast majority of women are struggling to make ends meet and take care of their families. Parts of this book will be most relevant to women fortunate enough to have choices about how much and when and where to work; other parts apply to situations that women face in every workplace, within every community, and in every home. If we can succeed in adding more female voices at the highest levels, we will expand opportunities and extend fairer treatment to all. Some, especially other women in business, have cautioned me about speaking out publically on these issues. When I have spoken out anyway, several of my comments have upset people of both genders. I know some believe that by focusing on what women can change themselves-pressing them to lean in-it seems like I am letting our institutions off the hook. Or even worse, they accuse me of blaming the victim. Far from blaming the victim, I believe that female leaders are the key to the solution. Some critics will also point out that it is much easier for me to lean in, since my financial resources allow me to afford any help I need. My intention is to offer advice that would have been useful to me long before I had heard of Google or Facebook and that will resonate with women in a broad range of circumstances. I have heard these criticisms in the past and I know that I will hear them-and others-in the future. My hope is that my message will be judged on its merits. We can't avoid this conversation. This issue transcends all of us. The time is long overdue to encourage more women to dream the possible dream and encourage more men to support women in the workforce and in the home. We can reignite the revolution by internalizing the revolution. The shift to a more equal world will happen person by person. We move closer to the larger goal of true equality with each woman who leans in.