With Purpose Success, part 43

To encompass this broad new vision for a full life after your primary career, the definition of retirement is changing radically-even though the term itself appears too sticky to shed. For better or worse, "active retirement" seems to be entering the lexicon to describe this new stage of life. But I prefer middlescence. Just as the new life stage of adolescence- the period between childhood and adulthood-emerged about a hundred years ago; middlescence-a period between adulthood and old age, say ages fifty to seventy-five-is surfacing today. 

For six million years humans didn't live much past twenty-five or thirty years of age. But in the past two hundred years our life span has tripled. 

Extraordinary breakthroughs-in public health, penicillin and other antibiotics, early immunizations for polio and other diseases, modern surgical techniques, and new pharmaceutical compounds-mean that more and more of us wake up each day with the idea that we just might live to ninety or even a hundred. And here's the thing: the best is yet to come. 

The longevity revolution is not over; it may even be picking up steam.

Just 160 years ago the elderly were a tiny fraction of the world population.

Back then, less than 5 percent of Americans and Europeans reached age sixty-five. The figure remained well below 10 percent as recently as 

1930. Now, projections have the number of sixty-five-year-olds globally doubling by 2050, at which time there will be more people over age fifty than under age fifteen, and the average fifty-year-old will be able to expect to live another forty-plus years. 

How far might this all go? One notable extremist, Dr. Aubrey de Grey, a computer scientist at Cambridge University in England, thinks we can extrapolate recent longevity gains far into the future. It may be possible for the human body to live several hundred years in an optimal environment, he believes. 

This is an admittedly radical prediction. But it points up just how much progress is taking place before our eyes. There is right now a wide and stunning range of promising research in medicine, from stem-cell breakthroughs to new pharmaceuticals to new hormone therapies and organ replacement and rejuvenation techniques. This work promises to lengthen your life for years beyond what you probably expect. Molecular biologist 

Cynthia Kenyon was able to double the life span of a worm by tweaking a single gene. She believes her work will eventually eradicate Alzheimer's and other age-related diseases. Scientists simply will not rest until they've found the fountain of youth, or at least the fountain of health. 

People commonly living to ninety or more will represent a challenging new frontier for mankind. We are explorers by nature, accustomed to harnessing our courage and resolve to cross a river, a continent, an ocean-the heavens-to discover new lands. Yet the longevity frontier poses a new kind of challenge. It's about exploring the space in your head and in your soul, not necessarily in just the world at large. What are you to make of your longevity bonus years? Do you tag them on at the end of life without changing what comes before? Why not distribute this longevity bonus at intervals along the way? Does your life cycle remain unchanged-learn, earn, retire-with the last part, old age, simply lasting longer? Or is a more interesting model beginning to surface-learn, earn, return? In this model you may use the "return" years to have and pursue new dreams and set energizing new goals for how to give something back.