It is not by muscle, speed, or physical dexterity that great things are achieved, but by reflection, force of character, and judgment; in these qualities old age is usually not only not poorer, but it is even richer.’

—Cicero (106–43 BC)

My mother in bed at fifty-two. My mother in bed at sixty-eight. When I lay the two images of her side by side, looking for the differences, at first there seem to be few. She was older, thinner, more wrinkled. Her hair, late to gray, was now sprouting a few silver strands here and there. These differences were subtle but present. Harder to spot: me at eleven - out of my depth; me at twenty-eight - still so.

At the end of her life, in the 1860s, when she had become the Grande Dame of Champagne, Barbe-Nicole wrote to a great-grandchild, “The world is in perpetual motion, and we must invent the things of tomorrow. One must go before others, be determined and exacting, and let your intelligence direct your life. Act with audacity.” Act with audacity! In other words, play to win.

We found scant evidence that the people in our study had an explicit goal of working until a target retirement age to be followed by a life dominated by leisure. The vast majority of people in this study remained engaged in some permutation of a hedgehog well past the age of 60, in some cases into their 70s, 80s, even 90s. That said, nearly half the people in our study had a “retirement” from one hedgehog partway through their lives and faced the challenge of transitioning to the next one. Sometimes these were relatively smooth transitions, such as Tenley Albright’s shift from skating to surgery.

I seem to have at least as much energy at 67 as I had at 37, perhaps even more. I need less sleep. I feel on the balls of my feet, tilted forward. I can't wait to get up before 5 a.m. and throw myself into each day. The inner fire burns brighter than ever. There are multiple elements that feed into this, including the sheer good luck of health to this point in my life. But now I see that one huge element has to do with this very project being an invigorating fusion of Extend Out/Circle Back. By taking on an entirely new subject at this stage of life, shifting from studying what makes great companies tick to studying people and what makes their lives tick, I’m clearly extending out. At the same time, I’m also circling back, returning to encoded operating modes I discovered years ago, particularly my penchant for doing big research projects, going from chaos to concept, and then writing and teaching what I learn. I’m incredibly energized by discovering entirely new elements of myself in doing this project and by how the study itself has changed me in such profound ways. I’m equally energized by circling back to activate and reactivate interests and encodings I’d discovered long ago.