Bill Gates

In the years since he stepped down from Microsoft’s board of directors, Bill Gates has committed his considerable brainpower—and considerable bank account—to philanthropic efforts around the globe, from eradicating extreme poverty to fighting deadly infectious disease. But Gates, 69, shocked the world in May when he announced that his massively influential Gates Foundation would not live on forever. Instead, it would close its doors by the end of 2045—and dramatically accelerate how quickly Gates would give his money back to society in a bid for maximum impact. In the man’s own words: “The clock starts now.” Read more: The Gates Foundation sets a deadline