In 1939, a young Sagan stood up to a neighborhood bully, swinging at the boy, missing, and shattering the plate glass window of a local drug store. Afterward, the drug store owner was solicitous, his own father proud of his pluck, and the bully more respectful—consequences that taught Sagan that “Sometimes it was good to fight back” (xi). As this happened at the start of World War II, Sagan’s mother was less pleased than her husband, and reminds her son about soldiers killing each other in Europe. Sagan, peering out the window over the Lower New York Bay, claimed that he could see them fighting on a distant strip of land. His mother dismissed this claim, setting the boy to ponder how it is possible to tell when another person is simply imagining.

Later that same year, Sagan’s parents took him to the New York World’s Fair, where he saw a "World of Tomorrow" made possible by scientific innovation. This early experience with scientific practice had a profound impact on Sagan, who credits his supportive parents with fostering his love of science despite not being scientists themselves, and introducing him to “skepticism and wonder” (xiii), the two fundamental ideas that underpin The Demon-Haunted World.