He had just completed a paper on juvenile obesity, titled “A Call to Action,” before his ill-fated plane ride. He was also in the midst of a two-year fellowship awarded to him by the Association of Teachers of Preventive Medicine.

“He was an extremely talented physician, researcher and policy maker with boundless energy,” said Dr. Sean David, who attended both Dartmouth and Harvard with Ambrose. “I believe he would have achieved the stature of Surgeon General or even a U.S. Senator had he been able to live out his career.”

More than anything, though, friends remember Ambrose’s warm and adventurous spirit.

“He was a joker and he was a lady’s man,” David remembered. “He was a hell of a good guy and this is not only a great personal loss but also to public health.”

Ambrose’s fun-loving ways were as much a part of his personality as his commitment to science.

“Paul was the only person I ever met who was as comfortable at a rave as he was at a conference on health-delivery deficiencies in appalachia,” said Christopher Durso, his best friend. “He was smart and funny and just completely himself, and one of the truest friends I ever had—the kind of friend who helps you know yourself better.”

Erin Fuller, who worked at the American Medical Student Association with Ambrose, said he was constantly active—whether he was practicing judo, rock climbing, reading or watching movies.