Tough Act to Follow: Every new version of The Tonight Show is inevitably compared to the one that preceded it; for example, Jay Leno's version was compared to Johnny Carson's version. Conan O'Brien's version was compared to Leno's first version, etc. Occasionally the hosts will call attention to this; after one music act, Leno quipped, "This is not your father's Tonight Show."
Unintentional Period Piece: Unavoidable, due to the monologue covering current event topics which can be head-scratching to younger viewers. This can even extend to the hosts themselves: In some shows during 1982, Johnny Carson complained about being in the news a lot lately. If you weren't alive at the time, he was referring to an incident where he was pulled over for drunk driving.
Tonight! America After Dark (1957) provides examples of:
