On a breezy evening this past weekend, I sat out on my patio, lit a sizable joint, and took little drags from it til the burn line singed my fingertips. When I stood up I was stoned, and I knew it; I rarely smoke pot, so when I do I really feel it. But how high was I, really? I reached for my phone, logged into an app called Druid, and took a five minute test. When I finished it gave me my results, which appeared in red: Your DRUID impairment score is 50.3.