Becoming a doctor, I hoped, would bring me back into the real world,” Sandeep Jauhar writes in “Intern,” his fine memoir of his training in a New York City hospital. “It would make me into a man.” The story he tells here is antiheroic, full of uncertainty, doubt and frank disgust, aimed at both himself and, sometimes, his patients. “Intern” succeeds as an unusually transparent portrait of an imperfect human being trying to do his best at a tough job.