One afternoon in January, Sean Penn answers the door of his Bay Area home, shoeless, in jeans and a gray thermal undershirt, his hair sort of crazily mussed, looking as if he's just woken up. It's a couple of minutes past noon.

To say that Penn has "aged well" is to employ a nonstandard usage of the term. He does not look younger than his 48 years. His forehead is baroquely creased, his long face haggard, his hair soaring and gray-streaked and parted down the middle.