Siva Sundaram got his first lesson in addiction before he started medical school, when he worked at a wilderness program for teenagers who suffered from substance use disorders. During his two years there, he came to realize the kids were just like him, struggling with the same problems of identity, peer pressure, and independence — and that people with addiction are no different from those with other illnesses. That insight served him well when he arrived at Harvard Medical School in 2015, just as the ground was shifting in medical education.