David Hockney was an enthusiast. He loved so many things (cigarettes, good-looking men, restaurants, opera, Picasso…). His great gift, and the secret to his enormous popularity, was his infectious communication of such passions, not just in conversation (he was a fabulous talker, fueled by a sly sense of humor, a wide-ranging knowledge and a curiosity about everything, including you), but in his art. A Hockney painting is marked by immediacy. You grasp at once what he is getting at.