Facebook is a really exciting place trying to do something really important that I really believe in. And it matters.

I have never met a woman, or man, who stated emphatically, "Yes, I have it all.'" Because no matter what any of us has—and how grateful we are for what we have—no one has it all.

Aggressive and hard-charging women violate unwritten rules about acceptable social conduct. Men are continually applauded for being ambitious and powerful and successful, but women who display these same traits often pay a social penalty. Female accomplishments come at a cost.

Facebook is a really exciting place trying to do something really important that I really believe in. And it matters.

Motivation comes from working on things we care about. It also comes from working with people we care about.

In those same 10 years, women are getting more and more of the graduate degrees, more and more of the undergraduate degrees, and it's translating into more women in entry-level jobs, even more women in lower-level management. But there's absolutely been no progress at the top. You can't explain away 10 years. Ten years of no progress is no progress.

We can each define ambition and progress for ourselves. The goal is to work toward a world where expectations are not set by the stereotypes that hold us back, but by our personal passion, talents and interests.