Green Acres - Season 2 - Eps 29: Who's Lisa?
While fixing the roof, Oliver accidentally drops a hammer on Lisa's head, giving her amnesia. Initially, he's upset because she doesn't even recognize him. He begins to suspect she's faking so he'll take her to New York for the opening of opera season.
About Green Acres

Title: Green Acres
First Air Date: 1965-09-15
Last Air Date: 1971-04-27
Status: Ended
Rating: 7.3/10 (from 65 votes)
Language: EN
Seasons: 6
Total Episodes: 170
Network: CBS
Genres: Comedy
Production Companies: Filmways Television, Orion Television, MGM Television, Filmways Pictures
Synopsis
Green Acres is an American sitcom starring Eddie Albert and Eva Gabor as a couple who move from New York City to a rural country farm. Produced by Filmways as a sister show to Petticoat Junction, the series was first broadcast on CBS, from September 15, 1965 to April 27, 1971. Receiving solid ratings during its six-year run, Green Acres was cancelled in 1971 as part of the "rural purge" by CBS. The sitcom has been in syndication and is available in DVD and VHS releases. In 1997, the two-part episode "A Star Named Arnold is Born" was ranked #59 on TV Guide's 100 Greatest Episodes of All Time.
Cast

Eddie Albert
Oliver Wendell Douglas

Eva Gabor
Lisa Douglas