Mr Smith goes to . . . meet Jerry Lewis

They're very good, the flunkies and major-domos at the Dorchester, but then, for £2,500 a night, they ought to be. That's the money that Jerry Lewis's suite was reportedly costing, and it may have been part of the package that a man in green morning dress held the door open and said, "Gentlemen, Mr Jerry Lewis" as the great man entered.

"Jerry Lewis looks a shock," I had been warned by Shawn Levy, who has written a book on the veteran Hollywood comedian. (Levy fell out with his subject to such an extent that to say he is non-authorised scarcely does the rift justice: he is Lewis's biographer non grata.) Sure enough, Lewis was swaddled in adipose tissue, a side effect of his medication. He looked like a man signalling from inside a Jerry Lewis dirigible in the Macy's parade.

Lewis's staff have replayed all his old films and TV specials - including the long-running franchise that paired him with Dean Martin in a matchlessly lucrative ham-and-rye combo; the (original) Nutty Professor; the moist-eyed charity telethons - and worked out that their employer made 1,795 professional pratfalls. At 76, Lewis was feeling every one of them, except when he self-administered painkillers via a control panel resembling a TV remote. "If I press this, the level goes up, if I press this it goes down. It also opens my garage," he wisecracked stoically. Lewis's medical history is almost as prodigious as his showbiz bio, and includes walk-ons for characters out of a Hunter S Thompson hallucination, such as "head of pain at Vegas General".

Every interviewer is properly solicitous of Jerry's health - unfortunately, the entertainer took ill backstage at the Palladium during his most recent visit to London - but if he's any sense, the journalist also worries about his own. In real life, Levy prepped me, Jerry can be as dead-eyed as the talk-show host he played in Martin Scorsese's King of Comedy. Topics to which he takes mic-hurling exception allegedly range from his marital track record through his work for good causes to a never-released film in which he played a clown in Auschwitz. (The latter doesn't make the toes curl quite so much when you remember that a European film of recent years and with a similar synopsis garnered awards.)

So I am relieved as well as pleased to report that the Lewis who spoke to Channel 4 News was the height of affability. Did he have any regrets? "I wanted to be a Viking," he deadpanned. In truth, he was wistful that he had turned down the Jack Lemmon part in Some Like It Hot, though graciously adamant that he would have ruined the picture. "Every year, Jack sent me a box of chocolates with a note: 'It was so nice you were so wrong.'"

For Levy, the puzzle about Lewis is why he keeps working. Said Lewis: "I have an almost religious belief in the performer up there on the stage. As mid-Victorian and saccharine as it sounds, I'm right, and I'll keep doing it till I die."