James Geary, deputy curator of the Nieman Foundation for Journalism at Harvard, is the author of ‘Wit’s End: What Wit Is, How It Works, and Why We Need It,’ ‘I Is an Other: The Secret Life of Metaphor and How It Shapes the Way We See the World,’ the New York Times best-selling ‘The World in a Phrase: A Brief History of the Aphorism’ and ‘Geary’s Guide to the World’s Great Aphorists.’ He likes to juggle.