In the developing world, they don't have smartphones yet. They have the older plastic phones, but women are saving money on those, because they don't have access to banks. Having that access to digital money changes everything for her because she actually doesn't have to negotiate with her husband, which she will tell you is very hard in these circumstances, especially when the means are meager. She's expected to have money to pay for the kids' health or to help with the school fees.

Bill [Gates] and I believe philanthropy can only be effective if it starts things and proves whether they actually work or not. That's the place that governments often don't want to, or can't, work.

When I studied computer science at Duke University in the first half of the 1980s, I had professors who treated women differently than men. I kind of got used to it. At Microsoft, I had to use my elbows and make sure I spoke up at the table, but it was an incredibly meritocratic place. Outside, in the industry, I would feel the sexism. I'd walk into a room and until I proved my worth, everyone would assume that the guy presenting with me had credibility and I didn't.

It's important to remember that behind every data point is a daughter, a mother, a sister—a person with hopes and dreams.

Make sure you continue to trust what you know now about yourself and stay true to what you believe in

I care much more about saving the lives of mothers and babies than I do about a fancy museum somewhere.

We started our foundation because we believe we have a real opportunity to help advance equity around the world, to help make sure that, no matter where a person is born, he or she has the chance to live a healthy, productive life.