Awesome Idiom of the Day -- Jumping the Shark

"The phrase jump the shark refers to the climactic scene in "Hollywood", the third part (written by Fred Fox, Jr.[4]) of a three-part episode opening the fifth season of the American TV series Happy Days in September 1977. In this story, the central characters visit Los Angeles, where Fonzie (Henry Winkler), wearing swim trunks and his leather jacket, jumps over a confined shark on water skis, answering a challenge to demonstrate his bravery. However, according to Henry Winkler, the fact of the matter is that his character, Fonzie, decided to jump the shark because he told Potsie he'd do it.[5] The series continued for nearly seven years after that, with a number of changes in cast and situations."

--Wikipedia