Airline pilots run through a printed checklist before every takeoff, even pilots with decades of experience who could likely recite it from memory. The checklist is not there because pilots are forgetful; it exists because memory under routine conditions is unreliable in a specific way, skipping a step without any felt sense that something was skipped. A pilot who relied on memory alone would not notice the gap until an instrument revealed it, which might be too late. Reading the list aloud and physically pointing to each switch forces a check that memory alone cannot guarantee.