Throwback!See Kaley Cuoco and the Rest of ‘The Big Bang Theory’ Cast Then and Now

Can you believe The Big Bang Theory has already been on TV for 10 seasons?! We can't!

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The hit show's cast — including Kaley Cuoco, Jim Parsons, Johnny Galecki, and more! — have changed quite a lot since the sitcom premiered in 2007.

Click through the gallery below to see the stars then and now!