The Mathematics of an Extraordinary Life

Dad on the roof October 2024.
He has dropped the flag pole on the roof so he
could fix a pulley.

A few weeks ago I wrote about my dad passing away the day after Christmas at 94 years and 9 months. My mom, at 93 years and 6 months, is adjusting to life without him after 72 years of marriage. Over the past couple of years, she has been dealing with dementia, with my father as her primary caregiver. Both lived independently in their own house until three weeks before his death. Three weeks ago, my father was still mowing an acre of grass weekly, snowblowing a 75-foot driveway, climbing on the roof to fix siding and shingles, and caring for my mother full-time.

When processing just about anything, eventually I look at numbers. Quantifying what my father accomplished gives me a way to understand the magnitude of what we lost. The statistics don't diminish the grief; they help frame it. They tell me that what felt extraordinary to us as a family was, mathematically, exactly that extraordinary. The numbers confirm what I already knew but couldn't articulate: my parents were a statistical anomaly, and us kids have been fortunate beyond measure. 

According to Social Security Administration actuarial tables, only 10% of males born in 1931 survive to age 94. Only 20% of females born in 1932 reach 93. The probability of both reaching these ages is roughly 2%. A 72-year marriage occurs in 0.1% of marriages.

But the physical capability is where the statistics become really remarkable.

In gerontology, my parents would classify as a "super-ager." Most people see sharp decline in functional capacity starting in their 70s. Fewer than 1% of 94-year-olds perform high-intensity tasks like roof work or operate heavy machinery while serving as a full-time caregiver.

My parents operated on what geriatricians call a "squared survival curve," maintaining a high plateau of health and performing at the physical level of people 20 to 25 years younger.

The combined odds: married 72 years, both alive at these ages, both living independently, my father performing high-risk maintenance and caregiving. 

Approximately 1 in 66 million couples.

They avoided the big three killers: cardiovascular disease, cancer, and neurodegeneration. They avoided the fall cycle that typically ends independence after age 80. They avoided the widowhood effect, where survival odds drop significantly when one spouse dies.

The Gompertz-Makeham Law of Mortality states that death risk doubles every 8 years. By age 94, my father should have been at 512 times the mortality risk of someone at age 50. His physical ability suggests his biological age was closer to 74, a 20-year gap representing the maximum observed in human biology.

Genetics played a role. Continuous physical loading maintained bone density and cardiovascular health that most people lose through retirement. Managing a household kept cognitive reserve high. Being married for 72 years provided massive protection against stress and isolation.

My mother now faces life without him, navigating both grief and the progression of her dementia. But she faces it with the same extraordinary resilience that carried both of them well past the boundaries that limit most lives. And she faces it having been cared for by someone who never stopped being her partner, even when the work became harder than climbing any roof.

The numbers tell a story of statistical improbability. But behind those numbers lived a couple that never stopped moving, never stopped working, and never stopped being there. The mathematics of their lives describe a couple of outliers. My experience describes an amazing married couple of people.