When Ole Kirk Kristiansen imported a newfangled contraption called a plastic-injection-­molding machine to Denmark in 1946, people thought he’d lost his mind. Kirk Kristiansen was a master carpenter who made wooden toys sold under the brand name Lego (abbreviated from leg godt, Danish for “play well”). The machine cost nearly 7 percent of the company’s annual revenue, but Kirk Kristiansen reckoned there was no limit to what he could manufacture with the new technology.