Could it be that retired people do not have to use an alarm clock but get up when they please, thus increasing the possibility of more hours of sleep. Retired people are also in the age group that most frequently get Alzheimer’s. Perhaps it is only co-occuring not casual?
I'd love to get a complete 7 or 8 hours of good sleep. As it stands now, I'll go to bed at about 9:30 then wake up at 3:00 a.m. and can't fall back asleep.......So I just lay there.