Experiments demonstrate that people are more distracted when they overhear a phone conversation—where they can know only one side of the dialogue—than when they hear two people talking. Curiosity is the secret of mystery novels' perennial success, and it prompts our interest in art and music; it is also the principal driver of scientific research. Even so, there is still no definitive consensus about why we are so curious, or about the mechanisms in our brain that are responsible for curiosity. Here Mario Livio investigates this most human of all our characteristics, interviewing scientists in several ?fields—including guitarist Brian May of Queen, a respected ?astrophysicist of late—and an astronaut with degrees in computer science, biology, literature, and medicine. Livio also profiles polymaths Leonardo da Vinci and ?Richard Feynman, seeking links between curiosity and genius.