There were a few things Nicholas Hoult didn't love about making the hit comedy About a Boy: Singing solo in front of 500 booing extras; being left out when costar Hugh Grant and some cast and crew played a high-stakes game of snooker. But for the 12-year-old veteran of a dozen British TV shows, nothing compared to the agony of his character's geeky haircut and thrift-shop togs. "It was like my mum stuck a bowl on my head, cut round it, then the bowl slipped and she got it wonky," Hoult says. "The jacket with the rainbow and the sunshine and the clouds—you would just never wear that out."

Needless to say, Hoult has little in common with Marcus, the preteen misfit who turns to Grant for guidance in Boy. "I stand up for myself more," says the seventh grader at London's Sylvia Young Theatre School. (He lives in nearby Wokingham.) His movie role, he adds, impressed his classmates—"for two days." It didn't buy him even that from his piano and voice teacher mom, Glenis, 49, his pilot dad, Roger, 50, or his three siblings. "If anyone starts to get bigheaded around here, there are enough of us to slap sense into him," Glenis says jokingly. "He is a boy at home."

"Which means struggling with his Spanish homework, mastering PlayStation and taking care of Foxy, his hamster in Boy, which director Chris Weitz gave him at the end of filming. Weitz also gave him the tacky jacket that makes him cringe as much as, oh, the thought of kissing a girl. "He's not a 40-year-old in a 12-year-old's body," says Weitz. "He's a 12-year-old in a 12-year-old's body. And that's really wonderful."