Editor’s note: This is another in a series of occasional columns by long-time Ann Arbor resident Robert Faber on what he describes as his most recently acquired area of expertise — growing old.

It all depends on whom you ask and the purpose or flavor of the conversation. For some, life begins at the moment of conception. For others, it is with the first kiss or the accumulation of the first million dollars in wealth (or some variation thereof, depending on the level of drive or greed). Or perhaps in finally breaking 100 at Radrick Farms golf course.

The defining moment in one’s life can be difficult to pinpoint, but generally the common thread is the discovery of a new horizon to explore or a new puzzle to solve or a new pleasure to pursue.

And although the particular accomplishment or challenge or puzzle that is discovered may vary according to its essence or the needs of the individual, the thrill of the transition need not be diminished by age. It is simply the fact of participation in a new search or the achievement of a new success or simply learning a new lesson — regardless of age — that registers.

And if that first moment of a new experience or the emergence of a new vision is difficult to recall, it is easy to categorize: it is the genesis of a new direction or purpose in life, a new interest in “tomorrow.”

For youngsters starting out on the Big Adventure, each sunrise is the prelude to a new escapade or to aspirations for new achievements or exciting new dreams. For kids under 50, who still have a lifetime of discovery ahead of them, new beginnings are accepted as part of the game.

But for seniors whose lives are often a rehash of what had gone before, there is much more hesitation to take the plunge.

The fact is, however, that there are many moments of discovery and growth still resting in each of us, regardless of age, just waiting to be coaxed out of our shadows.

Supportive evidence for this thesis comes from physician/author Oliver Sacks, who notes that most people who become proficient at new challenges later in life find a special joy in their accomplishment.

He uses the example of Eliza Bussey, a journalist in her 60s who could not read a note of music a few years ago. She says she then “trained my brain and fingers to form new synapses” and now studies harp at the Peabody conservatory, insisting that “my brain has dramatically changed” — a conclusion supported by Dr. Sacks.

Dr. Sacks then adds that, “simply thinking about an old problem in a new way, all of us can find ways to stimulate our brains to grow ... . Just as physical activity is essential to maintaining a healthy body, challenging one’s brain, keeping it active, engaged, flexible and playful, is not only fun. It is essential to cognitive fitness.”

And that is one of the secrets of keeping life sparkling rather than burdensome — finding and managing the next turn in our road.

Aesop (according to Shakespeare) identified seven stages in the life of Man, seeing “the world as a stage [with] each man in his time play[ing] many parts.” For many of those parts it is the anticipation of what comes next that most stimulates us — whether youthful problems of dating, or post-teen job-hunting, or middle-aged parenting.

It is dealing with the wide range of uncertainties in each of those stages — even in its most fragile late stages — that keep us intellectually alert and focused on the future.

And those same patterns of doubt and anticipation motivate even the most secure and successful among us. In his 80s, for example, billionaire T. Boone Pickens started making long-term investments in the production of wind energy, while fellow billionaire, 90-year-old Kirk Kerkorian, tried to buy Chrysler for $4.58 billion (presumably as security for his old age).

I hesitate to speculate on their motivation to gamble so heavily at their advanced ages, but I suspect it is the basic stimulation of competition, of pursuing still another tomorrow — rather than seeking a financial return on their investments — gives them the incentive to keep on going.

For those of us who have the interest and enthusiasm, but are a bit more limited in our investment portfolios, even our more restricted applications of time and energy are enough. The most irrational goals of the dreamy-eyed ancients among us have a role to play, because without them we exist as little more than fillers of space — and that is just not enough.

And that’s why “tomorrow” remains the hope for us all, regardless of need or skill or size of the prize. Because the alternative to planning and working for our future is simply to quit — and with that there is no pleasure and from that there is no return.

Bob Faber has been a resident of Ann Arbor since 1954. He and his wife, Eunice, owned a fabric store and later a travel agency. He served a couple of terms on the Ann Arbor City Council. He may be reached at rgfaber@comcast.net.