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See the cast of the show before they were stars, ahead.
Pictured here in 2004, Parsons made his on-screen debut in one episode ofEdin 2002.
Michael Yarish/CBS
He went on to appear in TV movies and pop up as Tim inGarden Statesoon after.
Johnny Galecki
Pictured here in 1990, Johnny Galecki started acting at the age of 12.
Mayim Bialik
Fans have known Mayim Bialik since she was a child star.
Djamilla Rosa Cochran/WireImage; Michael Yarish/CBS
Simon Helberg
Pictured here with Herve Villechaize in 1982, Simon Helberg started acting in the 1990s.
Melissa Rauch
Melissa Rauch found her spot onThe Big Bang Theoryas Bernadette Rostenkowski.
Ron Galella, Ltd/WireImage; Michael Yarish/CBS
Mark Mainz/Getty Images; Michael Yarish/CBS
Ron Galella, Ltd./WireImage; Michael Yarish/CBS
CBS; Michael Yarish/CBS
Betty Galella/WireImage; Monty Brinton/CBS
Mary Sue Bonetti/WireImage; Michael Yarish/CBS
