Dr. Sanjay Gupta made headlines with his mea culpa report about marijuana. This was a major about-face for Gupta, who'd long taken a position against pot use. "I was too dismissive of the loud chorus of legitimate patients whose symptoms improved on cannabis," he wrote. "Instead, I lumped them with the high-visibility malingerers, just looking to get high." Gupta's hour-long report did as much to advance the cannabis cause as any reform group this year.