He only cares about what's trending now. The only worthy examples are this week's examples, or even better, tomorrow's examples.
The zeitgeister will interrupt a long-term strategy discussion to talk urgently about today's micro-trend instead. The zeitgeister has little or no knowledge of the foundations of his industry, merely an out-of-context understanding of today's state of the art. He's encouraged by the media, of course, because the media are in the zeitgeist business. It's easier.
The challenge, of course, is that the momentary zeitgeist always changes. That's why it's so appealing to those that surf it, because by the time it's clear that you were wrong, it's changed and now you can talk about the new thing instead.