Maybe so, but in a business known for supersize egos, Gyllenhaal's small acts—like his tendency to let everyone else go through the catering line before him during the two-month shoot for Mile in Massachusetts and L.A. last year—did not go unnoticed. "Everyone had crushes on him—wardrobe, makeup, everybody," says his costar Aleksia Landeau, 27. "He's not like those actors who are like, 'Look at me!' He has a poetic soul. He lets people come to him."
Like directors, for starters. Since making his film debut as Billy Crystal's son in 1999's City Slickers, Gyllenhaal (pronounced JILL-en-hall) has racked up credits that belie his 21 years—from playing NASA engineer Homer Hickman Jr. in 1999's October Sky to his acclaimed turn as a store clerk who seduces Jennifer Aniston in The Good Girl. Yet it was more than his résumé that won over Oscar winner Sarandon, who plays the mother of Gyllenhaal's murdered fiancée in Mile. The activist actress was impressed when Gyllenhaal refused to appear in a commercial for a corporation with a dubious environmental record. "He's gorgeous, he's smart—and he's thoughtful," she says. Not to mention a cutup. After a 20-hour day on-set, the veteran performer couldn't pull herself together to film one final scene for Mile in the face of a giggling Gyllenhaal. "He'd look at me and I'd look at him, and we'd crack up," she says. "We never filmed the scene."
Gyllenhaal's self-proclaimed "goofy" spirit also won over Dustin Hoffman (who plays his fiancée's father). "Success hasn't changed him; he's retained his own unique, personal insanity," Hoffman says with a chuckle. "He has a great sense of himself."
A result, no doubt, of what Gyllenhaal has called his "dramatic, outspoken" family: director father Stephen (Losing Isaiah), screenwriter mother Naomi Foner, 56 ('88's Running on Empty), and actress sister Maggie Gyllenhaal, 24. Born in L.A., Jake "was a regular kid," says Jamie Lee Curtis, a family friend. "He didn't walk around with a Future Movie Star button." Still, when Jake was 13, his father gave him a role in 1993's A Dangerous Woman (scripted by his mother), and he caught the bug. After graduating from L.A.'s Harvard-Westlake School in 1998, he headed to Manhattan to study Eastern religion at Columbia University and worked as a busboy and a sous-chef to help pay rent. Two years later he dropped out and returned to L.A. to act. "Jake is more honest with me than anyone else in my life," says Maggie, a Manhattanite who starred with her brother in last year's Donnie Darko and currently appears in the indie drama Secretary. "We did fight as kids," she says, but now "he's one of my best friends."
Since their careers keep them on the move, the siblings have been getting by mostly on phone chats—but Jake gets more quality time with his parents. In between shoots, he unpacks his bags—and makes his famous home-cooked meals—at either their house on Martha's Vineyard or their place in L.A., where Maggie, too, still has a room. As Curtis says, "They're a very rooted family." Next month Jake heads to Montreal to film the action adventure The Day After Tomorrow with Dennis Quaid. Until then, he keeps busy reading ("I'm slogging through David McCullough's biography of John Adams," he says), listening to Coldplay and Eminem and hitting L.A. hot spots like Les Deux Cafes. Previously linked with actress James King, he is now happily single, says Mile director Brad Silberling. "He gets to stay out late and not have to come home and feed the dog or the baby." Not that he'll mind when the time comes, Silberling adds: "He's a generous soul."
Alexis Chiu and Julie Jordan in Los Angeles and Natasha Stoynoff in Toronto