My dad celebrated his 80th birthday a few days ago. Eighty years old is a pretty big milestone, and it got me thinking about something slightly uncomfortable: How many years does he have left? And maybe more importantly… How many do I have left? I know—it’s a morbid thought. But when you have aging parents and a lot of time to think, mortality tends to sneak into your brain whether you invite it or not. That curiosity led me down a rabbit hole researching life expectancy. I w