They started off by talking about Quentin Tarantino, so I zoned out as best I could - not a fan. When I fell back into the conversation they were discussing how a critic had said dear old Quentin had 'jumped the shark'. As neither of them knew what that meant they went back and forth trying to figure it out. It was all I could do to keep from laughing.
I really wanted to stick my oar in and tell them what it means:
"Excuse me, but jumping the shark is a term used to describe a moment when somethin that was once great has reached a point where it will from that point onwards decline in quality and popularity. The phrase originated from a Happy Days episode where the Fonz jumped over a shark on waterskis. This was seen as the lowest point of the show."
...but, of course, I didn't.
Hell, the term has its own website!