So every day for 40 years she would have read and thought carefully about that warning label, so that finally when it became relevant it would save her? Unfortunately not: we humans cope with the enormous stream of information pouring relentlessly through our senses by ignoring almost any unchanging signal. In industries requiring constant awareness for rare events, such as piloting highly automated aircraft or scanning luggage for bombs, we've learnt to present constant challenges (fake alerts, etc) to keep the operators paying attention. See also: safely driving a Tesla on autopilot...