Two things that I think matter are gratitude and joy.

Go to a playground: Little girls get called 'bossy' all the time, a word that's almost never used for boys. And that leads directly to the problems women face in the workforce. When a man does a good job, everyone says, 'That's great.' When a woman does that same thing, she'll get feedback that says things like, 'Your results are good, but your peers just don't like you as much' or 'maybe you were a little aggressive.'

I'd worked on leprosy and malaria in India [at the World Bank] and asked myself the question: Why do we let 2 million children die every year around the world for not having clean water? Because they're faceless and nameless. So, for me, Facebook looked like it was going to solve the problem of the invisible victim.

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.

I feel really grateful to the people who encouraged me and helped me develop. Nobody can succeed on their own.

Fortune does favor the bold and you'll never know what you're capable of if you don't try.

Speak up. Believe in yourself. Take risks.