Alexandra Holden was more than a little nervous. A newcomer to Hollywood from Northfield, Minn., the 23-year-old actress had only a month earlier landed the role of David Schwimmer's girlfriend on NBC's megahit Friends. She was strolling the Warner Bros. Burbank lot in March when a strange man in a golf cart pulled up beside her and began chattering away. "He was wearing a workman's jumpsuit and he had white hair sticking out of this old hat," recalls Holden. "Everyone was like, 'Call security! There's a weird old man around.' Then he put his hand out to me and said, 'Alex!' And I thought, 'This is a crazy old man.' " But just as she began to pick up her pace, she took a last glance at the wizened face. "And then I saw it: the smirk. The little smirk was still there underneath all that makeup," says Holden with a chuckle. "It was Bruce."

Security, for the time being, could rest easy. After all, at 45, Bruce Willis qualifies merely as a crazy middle-aged man. Still, even without the stage makeup -- applied for his role in this summer's The Kid, filming at the same studio -- much has happened in the 16 years since his wry grin morphed into the Smirk while he bantered with Cybill Shepherd on ABC's hugely popular Moonlighting. There have been the lows: 1990's Bonfire of the Vanities, 1991's Hudson Hawk, even last year's lackluster Breakfast of Champions. There have been highs, like the three Die Hard movies, which turned Willis's character, New York City cop John McClane, into a one-man box office demolition team. And there have been lows that spawned extraordinary highs: Disney's $17 million bailout of Willis's never-finished 1997 genre comedy Broadway Brawler forced him to star in 1998's Armageddon, the year's top box office draw at $520 million worldwide. It also landed him in a little picture called The Sixth Sense, one of the 10 top-grossing films of all time at $643 million and counting, in which a melancholy Willis stood a hoary Hollywood rule (Never star opposite a child) on its head and earned an estimated $60 million while doing so.