In Dirty Rotten Scoundrels, an aspiring con-artist, played by Steve Martin, learns to pour, savour and pose with champagne. To promote the film, it was arranged for select journalists to rendezvous one morning in 1989 in the Bessborough suite of London's Grosvenor Hotel, to sip bubbly with Martin. "Sometimes I dread having to be funny," he announced, once he'd ordered room service and four hotel staff – impersonating him – had knocked at his door wearing joke arrows through their heads. "I had lunch with Paul McCartney yesterday." he noted. "I never thought I'd be having lunch with Paul McCartney."

Born in Waco, Texas, raised on frozen Birds Eye meals and paternal beatings, as a youth he'd finally cried – "with joy" – while chopping onions, before taking a philosophy major and beginning stand-up at San Francisco's Coffee & Confusion cafe. Now he was a $12m-a-year movie star. "One of the good points of celebrity is being able to get tables at restaurants," he advised. "One of the bad points is being video-taped while eating."

His Beverly Hills home had no windows on its front – the message, he explained, was, "Go away". I asked him which items among his considerable wine and modern art collection he'd save in a house fire. He looked distressed, then admitted, or joked: "The first thing I'd reach for is the insurance papers."

After one early stand-up performance, Martin led his audience to a McDonald's and ordered 300 burgers, then changed his order to one portion of fries. Today he beckoned us to Grosvenor Gardens where he posed with a steak house in the background. There I requested he write "Go Away" on a silly photo of himself. He debated the implications, then told me he shouldn't and wouldn't.