The discovery of the sketch inspired us to have a day-long conversation, then start a three-year research journey, and eventually write a book,Like: The Button That Changed the World.Alas for Bob, our research was unable to identify a single clear inventor of the thumbs-up button, but that’s part of what makes its origin story so instructive. Indeed, the button’s design, development, and deployment could be considered a miniature case study on the true nature of innovation—which is distributed, unpredictable, and often far more modest in ambition than heroic innovation narratives suggest.