In this file photo of Jan. 24, 2013, Melinda Gates chats with Sharmila Devi, who had recently given birth to a girl (carried under her shawl), at her home in Dedaur village in the Bakhtiarpur block of Patna district. On Sharmila’s right is her mother-in-law, Lal Muni Devi.
Growing up in Texas in the 1970s, I always knew I wanted a career in computer science. That required a little imagination because I didn’t know a lot of women who worked outside the home or who had careers like the one I aspired to. But I was lucky. I had a mother who encouraged me to be anyone or anything I wanted to be–and a father who insisted that being a girl should never put a limit on my dreams.

My dad even made a point of introducing me to a woman he worked with–an engineer he described as one of his most respected colleagues–so that I could see for myself that women’s contributions and ideas are just as important as men’s. Even today, society doesn’t always give young women that message. So I was fortunate to have a father who did.

With my parents’ support, I earned degrees in computer science and business and spent a decade as a software executive at Microsoft–and I’ll always be grateful to them for that. But their support didn’t just turn me into a computer scientist. It taught me what it means to be an advocate for women and girls. And through their example, my parents also taught me the value of giving back to society from an early age.

Now, as co-chair of the Bill & Melinda Gates Foundation, I’m trying to put these lessons into practice to help unlock the potential of women and girls around the world.

Over the past decade and a half, I’ve spent a lot of time in developing countries. It’s the best part of the job–meeting people, being invited into their homes, hearing their stories and learning about their lives. One thing I’ve found is that no matter where I am in the world, I’m always able to form a special connection with other mothers.

By many metrics, there has never been a better time to be born a girl. The data tells us that that in virtually every country, women are living longer, healthier, better lives than ever before. But it also confirms what we know from our daily experiences: There is a long way to go to reach true gender equality.

All around the world, women and girls still learn less, earn less and have far fewer opportunities to live healthy lives and participate fully in their communities. This was brought home to me in India last year when I met 6-year-old twins, Krishna and Radha. Their lives will be very different simply because Radha is a girl in a community where sons are favored over daughters. But the truth is that when girls can reach their full potential, everyone benefits, including boys and men.

Investing in women and girls isn’t only the right thing to do–it’s the smart thing. Empowering women and girls through better health, more decision-making power, and economic opportunity helps save lives, makes families more prosperous and builds stronger economies. That’s because women invest the majority of every dollar they make back into their families and prioritize the household budget for healthcare, nutritious food and education–the building blocks of thriving societies.

Women know what’s best for themselves and their families–and they need the power to act on that. When a woman can decide whether and when to get pregnant, both she and her family are healthier and her children are more likely to break out of poverty. But there are still 225 million women in the world without access to any form of modern contraceptives. I’m determined to change that. And our foundation is committed to getting tens of millions more women and girls access to family planning by 2020.

The good news is that we’re seeing unprecedented momentum to advance gender equality. Prime Minister Shinzo Abe–a great champion for women’s empowerment–is leading by example. When we met at the United Nations last year, he told me of his commitment to building “a society where women can shine.” And in March, International Monetary Fund Director Christine Lagarde and I sat down in New Delhi with finance ministers and central bankers from across Asia to encourage them to invest even more in women and girls.

I like to call myself an impatient optimist. I know progress is possible because we see it happening already. But I also believe that we all have a role to play in speeding it up. Foreign aid from the United States, Japan and other Group of Seven nations can do a lot to build healthier, more prosperous communities in developing countries–and that leads to a better future for all of us.