You would need a sturdy pair of water skis and some very good luck to actually jump over a shark in the ocean. This is exactly what happened on one American TV comedy show several years ago. However, fans and other TV viewers felt that this silly and improbable action was a kind of cheap trick to get attention because the program's writers had run out of truly clever ideas.

Later, the idiom "to jump the shark" became a way to indicate the precise moment when you realize a program, band, actor, politician, or other public figure has become forever less attractive, gone downhill, and will never be as good as in the past. In business or social relationships, the term means a defining point in which a boss, spouse, friend or lover behaves in a foolish or untrustworthy way that destroys their credibility, removing your desire to continue that relationship any longer.