Speaking with a zygote recently, I mentioned the brilliance of Henry Winkler hopping over a shark on Arrested Development. I then had to explain to my audience that before she was born (and shortly after Jaws came out), Winkler donned a leather jacket and water skis and jumped a shark. The shark. This moment spectacularly signaled the beginning of Happy Days' demise. Never great, from this moment on, the show went on to become absolutely excruciating drivel. Hence the expression.
Whether it's your first time or a wincing reminiscence, enjoy.