If there's any single force behind the wild range of Warhol's art, it is his hatred of the already done.
Philip Pearlstein remembered that, more than anyone else in their clique, the young Warhol believed "that you should always try to find something new." This idea, so central to Warhol's entire career, wasn't something he was born with; we can track him learning it as a student aesthete in Pittsburgh. A teacher of his at Tech is supposed to have laid down the law to him: "You have got to do things the way you want them, and be damned with what I think, be damned with what anybody else around you thinks. Go do it the way you see it, to please yourself, or you'll never amount to anything."
Warhol, lake Gopnik, page 65