Philanthropist and business leader Melinda Gates is known for using her fortune and platform to give back. But, even before becoming one of the world's most powerful women, the 56-year-old told The New York Times that she's always thought about how she could use her life to help those in need.

As the valedictorian of her high school class, Gates said she read a Ralph Waldo Emerson quote during her graduation speech that has had a huge impact on her success as a philanthropist today.

"To know even one life has breathed easier because you have lived," she told her classmates, "this is to have succeeded."

That quote, she told the Times, is one that still sticks with her today as the co-chair of the Bill and Melinda Gates Foundation and the founder of an investment and incubation company called Pivotal Ventures.

"That's been my definition of success since high school," she explained. "So if I have an extra dollar, or a thousand dollars, or a million dollars, or in my case, which is absurd, a billion dollars to plow back into making the world better for other people, that's what I'm going to do."

As the wife of Microsoft co-founder Bill Gates, the mom of three has worked alongside her husband to be an advocate for better health care worldwide. Since starting their foundation in 2000, the billionaire couple has spent an estimated $40 billion on global health development, including helping to fight diseases like malaria and polio.

This year, the couple has donated more than $300 million to help find treatments and a vaccine for Covid-19, with Bill saying earlier this month that six vaccines could be available by spring 2021.

In addition to working to ensure better global health care, Gates has also used her fortune to increase economic opportunities for women. In October 2019, she announced that she was committing $1 billion over the next 10 years to "to expanding women's power and influence in the United States."

"I want to see more women in the position to make decisions, control resources, and shape policies and perspectives," Gates wrote in a 2019 op-ed for Time. "I believe that women's potential is worth investing in — and the people and organizations working to improve women's lives are, too."

When reflecting on the enormous privilege that she and her husband have as billionaires, Gates says "there's no explanation how you get to be in this situation." But, she says she spends a lot of her time meeting with people around the world and listening to their needs and asking herself, "How do I take what that person shared with me and what I learned, and how do I plow that back into the work to try and make the world better...?"

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