… Then along came the Mark Zuckerberg of his day, Johannes Gutenberg. As we became accustomed to relying on the printed page, the work of remembering gradually fell into disuse.

But this comparison between Gutenberg and Zuckerberg makes little sense unless you realize that Keller is actually trying to complain about the reemergence of oral psychodynamics in the public sphere rather than about memory falling out of favor. If the latter were the case, his ire would be more about Google; instead, most of his frustration is directed against social media, and mostly Twitter, the most conversational, and thus most oral of these mediums.