People generally have an intuitive understanding of the security properties of doors. On the other hand, my mid-70s in-laws still have not internalized the idea

People generally have an intuitive understanding of the security properties of doors. On the other hand, my mid-70s in-laws still have not internalized the idea that the threat model for bad / reused passwords is not "some guy sitting at a computer randomly trying passwords". A better example for the door analogy would be that you leave it unlocked so you can grab something out of the car in your driveway, and by the time you get back someone from Russia has taken all your stuff.