“Not so long ago it seemed as if we all spoke the same pop-culture language. But in an era of 500 TV channels, billions of Web pages, unlimited Netflix rentals, and iPods with music libraries of Smithsonian proportions, popular entertainment has suddenly become mind-bogglingly vast. As the overlap between what we all watch, read, and listen to steadily erodes, the water cooler has become a modern-day tower of Babel, where conversations sound like the jumbled voices emanating from the jungle in “Lost.” (If that reference is lost on you then, well, Q.E.D.)”