Playing lanky, geeky freshman Steven Karp on the new college comedy Undeclared isn't a stretch for 19-year-old Jay Baruchel. Take it from someone who knows. "That character is my son!" says his mom, Robyne, 47. "Jay is nervous and unassuming and easily embarrassed."

Despite starring in the critically acclaimed FOX series, Baruchel remains very much a typical teen. Amid the mess of his scantily furnished bachelor pad, he survives on fast food and offers visitors M&M's as hors d'oeuvres. "I have Coke too," he says sheepishly. "Though it's a little flat." Since moving to L.A. last fall, the actor admits he still pines for Montreal, where he grew up with sister Taylor, 14. The son of Robyne, a freelance writer, and Serge, 46, an antiques dealer, Baruchel got his professional start in Canadian TV series, but it was his small role as a loopy Led Zeppelin fan in last year's Almost Famous that caught the eye of Undeclared creator Judd Apatow. "He's a very in-the-moment actor," says Apatow. "His lines and reactions don't feel scripted." Baruchel, who will also be seen in next year's film The Rules of Attraction, with James Van Der Beek and Jessica Biel, explains it more simply: "I'm insanely lucky."

Though perhaps not with women. "I'm not suave, no way," says Baruchel, who has no girlfriend and spends much of his downtime playing video games. "I haven't even figured out how to flirt."