The best answer is probably (d) all of the above. A 19-year-old with a taste for cheap—or, more accurately, bargain-basement—puns, Smith plays Ephram Brown, a piano prodigy who's mad at his widowed dad (Treat Williams) for uprooting the family from Manhattan to a small Colorado town. Despite their scripted shouting matches, off-screen, "I consider him a close friend," says Williams. "The fact that we can work so hard and still spend the weekend boating together is good."
His real dad, Maurice, 63, a British film producer separated from his mom, Terrea, 49, an American substitute teacher, when Greg was 12. Growing up, "he was naive about the world," says Maurice, "because he was working in this kind of bubble"—in films like 1992's Patriot Games and 2001's American Outlaws. "I was concerned how he'd do on his own, but he's okay." Mostly okay, anyway. Unattached in L.A., "I'm kinda like a big dork, so I'm always using cheesy pickup lines," admits Smith. "But if you can make them laugh, well..."