Penn Jillette is one-half of the magic duo Penn & Teller, who launched their act to great acclaim in the 1980s but have never stopped changing it. A performer on stage and screen for more than 40 years, he recently lost 100+ pounds, an experience chronicled in his new book, Presto!
A version of this article appeared in the October 2016 issue (p.128) of Harvard Business Review.