A book from a website eventually sold out to tvguide.com but still available in the Wayback Machine, Jump the Shark is all about TV shows, actors, singers, and politicians who all had a defining turning point in their times after which they were never the same. The term came from the author and his college roommates from a Happy Days episode where Fonzie literally jumps over a shark on water-skis.

Some interesting trivia in here, but mostly it reminds me I still have a long way to go on my cultural literacy. Maybe not so much to the point of watching every mentioned TV show, but I could still familiarize myself with some of the great singers and bands of the last few decades...