> If the average life expectancy is ~80 years, my parents are in their mid-60s, and I see them one time per year, the math—however depressing—says I will see th

> If the average life expectancy is ~80 years, my parents are in their mid-60s, and I see them one time per year, the math—however depressing—says I will see them 15 more times before they are gone. The fact that his parents survived until their mid-60s means that they have a life expectancy better than the ~80 year average, as that average includes many people that don't make it to their mid-60s.