By the time fans got to know Johnny Galecki as Leonard, he'd been acting professionally for years. As a child, he told people he wanted to be either an actor or a witch when he grew up (via Behind the Brand). His parents didn't see it (the acting career, that is) and tried to encourage other interests. "But I was very, very stubborn about it," Galecki recalled. He then saw an 8-year-old Ricky Schroder in "The Champ" and realized this was a career he could start right away. And he did, getting into theater, landing an agent, and moving to Los Angeles.
Throughout the 1980s, he appeared in TV movies and feature films, including 1989's "National Lampoon's Christmas Vacation." Through the 1990s, he had roles in TV series including "American Dreamer" from 1990 to 1991, "Blossom" in 1991, and "Billy" in 1992. But when "The Big Bang Theory" premiered in 2007, anyone wondering why he looked so familiar probably remembered him best from "Roseanne." On that long-running sitcom, he played Darlene's (Sara Gilbert) boyfriend, David, from 1992 to 1997.
Despite all of his success, however, Galecki had actually quit acting by the time "The Big Bang Theory" was under development. "My career has not been seamless," he told Entertainment Tonight. "Immediately before 'Big Bang,' I was in Wisconsin studying plumbing."
