Exponential Aging

We tell the age of a baby in months. Thirteen months, eighteen months: each month of a new life is dense with change, and the unit honors that density. Then, without anyone deciding it, the unit changes. Nobody says a child is a hundred and thirty months old. A ten-year-old is ten, and for a long stretch of life the year is the right measure of who we are becoming.

Today is my birthday, and I have stopped counting years.

I am sixty-one. But when someone asks how old I am, I answer seventy, because I round up to the decade. The decade is the unit that now carries the information. Between fifty-nine and sixty, something worth naming happens. Between sixty and sixty-one? The year has stopped being meaningful as a milestone, exactly as the month did when we were two.

And I plan to keep going. When I am a hundred and one, I will answer two hundred, because I will be in my second century, and by then it will make no sense to count anything smaller. Ask me again later, and we can start keeping track of the millennia.

I have been calling this exponential aging, though a mathematician would gently object that the yardstick is logarithmic. Both are right, because they describe the same curve from opposite ends. The units we use to count a life grow by orders of magnitude: months, years, decades, centuries. Plotting a life on that scale is what a logarithm does. Seen from the other side, for the units to keep growing, the life they measure has to keep extending, and that is the exponential view of a lifespan.

Our own perception already works this way. A year is a thirteenth of everything a thirteen-year-old has ever experienced, and a sixty-first of my life so far, which is part of why the years seem to accelerate as we accumulate them. We feel time proportionally, not absolutely. The units I am proposing simply make our spoken age honest to how a life is actually experienced: in chapters that grow with us.

Units are bets. To count a baby’s age in months is to bet that the next month matters enormously, and it does. To count decades is to bet that there are decades ahead worth planning for. To count centuries is to bet on the science of longevity delivering radical life extension, a bet I make openly and cheerfully, knowing I may lose it. My delusion is not to die. My goal, when I do, is to die with a lot of open projects.

None of this is denial, and it is not vanity either, since my version rounds up rather than down. It is a way of orienting toward the future with the same seriousness we grant the past. The billions of years that preceded us did not ask our permission to pass; the years ahead are the only ones where our thinking, doing, and being can make a difference.

So today I am seventy, give or take a rounding convention. The moment to think, to do, to be, is now.