"There is no real you," jokes Lynn Margulies (Courtney Love) to her boyfriend, Andy Kaufman (Jim Carrey), as he grows more contemplative during a battle with cancer. "I forgot," he says, playing along, though the question of Kaufman's reality is always at issue in Milos Forman's underappreciated Man on the Moon.

The story of Kaufman's quick rise to fame through early appearances on Saturday Night Live and the conceptual stunts that made his club and concert appearances an instant legend in the irony-fueled 1970s and early '80s, Man on the Moon never makes the mistake of artificially delineating Comic Andy from Private Andy. True, we get to see something of his private interest in meditation and some of the flakier extremes of alternative medicine, but even these interludes suggest the presence of an ultimate con behind apparent miracles of transformation.

Screenwriters Scott Alexander and Larry Karaszewski ( The People vs. Larry Flynt) allege that transformation was Kaufman's purpose--more than a shtick but less than a destiny. As we see him constantly up the ante on the credibility of his performance personae (the obnoxious nightclub comic Tony Clifton; the insulting, misogynistic professional wrestler), Forman makes it harder and harder to detect Kaufman's sleight of hand. But it's there, always there, always the transcendent Andy watching the havoc he creates and the emotions he stirs.

Carrey is magnificent as Kaufman, re-creating uncannily detailed comedy pieces etched in the memory of anyone who remembers the real Andy. But while Carrey's mimicry of Kaufman is flawless and funny, the actor probes much deeper into an enigmatic character who, in life, was often a moving target even for those closest to him. -- Tom Keogh