Hans Rosling (1948-2017).

Like a lot of Hans Rosling's admirers, we discovered his work via his famous 2006 TED talk, “The Best Stats You've Ever Seen.” It was a mind-blowing speech (with more than 11 million views to date) with innovative graphics, good jokes, and a profound message: The world is getting better, and even some of the poorest countries are making progress. Hans was a showman, but he didn't sacrifice an ounce of complexity. He was—and this is a term of honor in our house—a data nerd. We sang his praises to just about anyone who would listen. Soon after his TED talk, we had a chance to meet Hans in person. He joined two health ministers for a meeting at our foundation in Seattle, and we hosted them for dinner at our house one night. We asked a lot of questions, listened, and learned—from everyone, and especially from Hans. We lost track of the time, and eventually one of us leaned over to the other and whispered, “We have to take the kids to school tomorrow!” As we said our goodbyes, we hoped we would get to know Hans even better. Over the years, we did. Hans led a remarkable life. He was born in Uppsala, Sweden, in 1948, the only child in a working-class family. He met his wife, Agneta, in grade school, when they were both 7 years old. They basically ignored each other until they were 13, when they ended up in the same biology class. On the first test, Agneta earned the top grade. That got Hans's attention—which tells you how unusual he was, even as a teenager. Agneta would go on to forge her own impressive career in health care. Hans adored her and their two children, Ola and Anna. ![Figure][1] PHOTO: TOMMY HVITFELDT In 1979, a few years after Hans finished studying medicine at Uppsala University in Sweden and public health at St. John's Medical College in Bangalore, India, the family made their way to Nacala, Mozambique, where Hans was one of two physicians for 300,000 people. He zeroed in on a subject that would occupy the next two decades of his professional life: outbreaks of spastic paralysis, or konzo, a crippling condition that makes patients' legs so stiff that they can't walk. The research he led—grounded in both gathering data and understanding the practical realities of people's lives—helped establish a key link between konzo, malnutrition, and the consumption of improperly processed cassava. Many years later, Hans would employ those same skills during an even bigger public-health crisis, the Ebola epidemic of 2014–2015. In October 2014, the world was still trying to understand how many cases there were. Questionable data was hampering the response. Hans thought he could help, given his deep experience combining data with an understanding of how people actually live. He canceled all his speaking engagements and packed his bags for Monrovia, Liberia, one of the focal points of the Ebola fight. Giving up those speeches was a financial hardship for his family. He hated being apart from Agneta for so long. He wasn't even sure he would have a desk to work from. By this time, Hans was a fixture on lists of the world's most influential thinkers, but he didn't hesitate to head for the front lines. He cared only about saving lives. In his career, Hans wore a lot of different hats—physician, statistician, speaker—but the one he embraced the most was “teacher.” He made it the focus of the second half of his career and was deeply proud of the students he mentored at Karolinska Institutet in Sweden. The two of us were lucky to learn from him, too. He would offer advice on a presentation, or gently nudge us with questions about our foundation's strategy. And he steadfastly encouraged me (M.G.) in my work to empower women and girls. We cherished his wisdom and his friendship. The last time either of us saw Hans was last May. He had terminal cancer, and I (M.G.) went to visit him at his home in Sweden. He delivered a final, heartfelt message. He pulled out a sheet of paper and drew a map of a typical village. He sketched in some roads, two rivers, and the center of the community. Then he drew circles at the far edges of the map and said, “This is where the marginalized people are. If you want to reach your goals, you must keep going to the margins of society.” It was a lesson he had learned years before, in Mozambique, and he wanted to share it one last time. Throughout his illness, Hans was somehow both matter-of-fact and upbeat. “One day I will die,” he would say. “All the others, I will live.” He lived until 7 February 2017. In a way, it's ironic that Hans became famous as a master of data. Of course, he cared about statistics, but that's not what really moved him. As he once put it, “I'm in this because once upon a time, I learned what deep poverty was. It wasn't a number struggling to feed another number. It was a mother trying to feed her child. Then I counted, and I saw it wasn't one woman who was badly off. It was the entire village. It was half of the country. It was 800 million people in the world. Those ain't numbers. They are people.” Hans Rosling loved data, but even more, he loved people. [1]: pending:yes