A Scanner Darkly by Philip K. Dick

Again Fred spun the tape forward a full hour.

"—this guy," Luckman was saying, manicuring a box full of grass, hunched over it as Arctor sat across from him, more or less watching, "appeared on TV claiming to be a world-famous impostor. He had posed at one time or another, he told the interviewer, as a great surgeon at Johns Hopkins Medical College, a theoretical submolecular high-velocity particle-research physicist on a federal grant at Harvard, as a Finnish novelist who'd won the Nobel Prize in literature, as a deposed president of Argentina married to—"

"And he got away with all that?" Arctor asked. "He never got caught?"

"The guy never posed as any of those. He never posed as anything but a world-famous impostor. That came out later in the L.A. Times—they checked up. The guy pushed a broom at Disneyland, or had until he read this autobiography about this world-famous impostor—there really was one—and he said, 'Hell, I can pose as all those exotic dudes and get away with it like he did,' and then he decided, 'Hell, why do that; I'll just pose as another impostor.' He made a lot of bread that way, the Times said. Almost as much as the real world-famous impostor. And he said it was a lot easier."