You, like me, may never have realized how many voices on The Simpsons are done by two guys. Everyone knows Homer’s voice (done by Dan Castellaneta), but did you know he also does Grandpa Simpson, Crusty the Clown, Mayor Quimby and Groundskeeper Willy? Or that the Mr. Burns and Smithers are done by the same guy (Harry Shearer), amongst various others? Check out this clip from Conan O’Brien.