If anybody here has trouble with the concept of design humility, reflect on this: It took us 5,000 years to put wheels on our luggage.

McDonough’s remark uses a homely example—the late arrival of wheeled suitcases—to puncture the myth that human “design” is automatically smart, inevitable, or steadily progressive. The phrase “design humility” frames innovation as something that should begin with modesty: if an improvement this obvious can take millennia to become commonplace, then today’s designers and institutions should be wary of overconfidence, premature claims of optimization, and the assumption that current systems are the best possible. In McDonough’s broader sustainability ethos, the line also implies that better design is often less about heroic novelty than about noticing overlooked, practical changes that reduce friction and waste in everyday life.