Once folks get the notion that half of people will outlive the average life expectancy of their age group they could die before 80 or after 80 they need to revisit their financial planningtimehorizon.
This proposition comes directly from economic theory, which says that people respond to the risk of dying not by shortening their planninghorizon and blithely assuming they will die right on time, but by choosing to consume somewhat more when young and somewhat less when old, if they do end up living longer than expected.