Like his friends Merce Cunningham and John Cage, Johns subscribes to what you might call the cult of impersonality. He particularly dislikes biographical interpretations of his work. And yet, he told an interviewer in 1978 that "I certainly believe that everything I do is attached to my childhood." That childhood was by all accounts miserable and lonely. His parents divorced when he was a toddler, and he was shuffled between the South Carolina homes of his grandfather and stepfather; at age 10 he was sent to live with a schoolmarm aunt in a nondescript hamlet known only as the Corner. "Most of the time," he told Calvin Tomkins in a recent New Yorker profile, "wherever I lived, I felt like a guest." Solace came from making art. An art teacher at the University of South Carolina, where he enrolled in 1948, more or less adopted him; he recently purchased her dining room table. The materials of childhood art classes, as in this do-it-yourself target, are ubiquitous in his paintings and collages. As Sylvester observed: "So many of his initial themes—flags, targets, numbers, letters, maps, rulers, and … certain techniques—such as rubbing, finger painting and tracing—belong to the schoolroom." Cage's influence is also evident in the invitation to do it yourself. Art is something you do, and anyone can do it. Just take a ruler, that device for drawing straight lines and for keeping dancing teenagers apart, shorten it by a couple of feet, add a metal cup, and …