Who Am I?

S1 E18: A familiar old sitcom ploy is given a new twist in this episode. After being accidentally struck on the head with a wrench, Uncle Martin (Ray Walston) suffers from total amnesia. This of course means that, among other things, he refuses to believe that he's a 450-year-old visitor from Mars! Tim (Bill Bixby) races against time to restore Martin's memory so that he can link up with a rocket expert who may be able to help him return to his home planet.