The real-world value of knowledge in the mobile-device age. More people know who Khloe Kardashian is than who Rene Descartes was. Most can't find Delaware on a map; don't know what Frank Lloyd Wright did for living; can't say how many calories are in a Big Mac or how many candles are on a menorah. How important it is to know things, anyway? William Poundstone uses Big Data survey technology to examine how knowledge relates to wealth, health, politics, and behavior. Head in the Cloud identifies the types of knowledge that still matter (and those that don't). It asks why Fox News viewers don't know which party controls Congress; why we're okay with spelling errors on menus but not on resumes; how we can navigate clickbait and media spin to stay truly informed. Head in the Cloud is a witty, practical guide to succeeding in a culturally illiterate age.