Sheldon Cooper may be a once-in-a-lifetime genius ... colleagues who were breaking the rules and how he was still "mostly angry" and a "little sad" about the incident. At dinner that night ...

"We did the very clichéd, in the beginning, goofy blonde who says foolish things," Lorre says of the character Penny.

The Big Bang Theory's prequel spin-off series, Young Sheldon, introduced Sheldon Cooper's dysfunctional but lovable family to the audiences.