Read more: The 15 Best '80s Comedies Ranked Ultimately, getting Wil Wheaton to join "The Big Bang Theory" in literally any capacity was a challenge, and Bill Prady had to take matters into his own ...

Then, at 18, Wheaton suddenly left Hollywood. He explains why he left and came back and how he came to play his evil self on The Big Bang Theory. Produced by Will Wei. Camera by Devan Joseph.

"The Big Bang Theory" brought us an unforgettable mix of science, friendship, and laughter that we're still talking about 18 ...