“Land ho!” I shouted. “There’s an island on the horizon!”

It was 1968, and I was 8 years old. To those outside my imagination, my sailboat looked like a willow tree and my ocean a bumpy stretch of Bermuda grass with a clothesline strung across it.

But in my fanciful head, I was not in landlocked New Mexico but on the vast blue sea, barking orders at my rapscallion crew. Every day was a new adventure, sailing on brisk sea breezes and exploring exotic landscapes.

These backyard play sessions were just symptoms of my adventurous spirit rearing up. My mother was constantly plucking me out of questionable predicaments, like when I was teetering on top of the upright piano at two years old or tumbling headfirst into a swimming pool when I was five.

And that sense of adventure was not something I outgrew. My territory just expanded. By my mid-30s, I had lived in eight states, visited 39 of them, and traveled to 11 countries — and that’s when I really upped the ante.

Those childhood imaginings were either prescient foreshadowing or dress rehearsals for the way my life played out some 40 years later. When I was 50, my husband and I sold all our possessions, our house, cars and wine shop and set off on a real sailboat, a rapscallion crew of two. Every day was a new adventure, sailing on brisk sea breezes and exploring exotic landscapes. Countless times in four years of sailing, we saw islands rise up on the horizon, more exhilarating than it had been from my willow tree cockpit, but without the reassurance of my mom’s PB&J sandwiches.

But the adventurous spirit doesn’t always exhibit itself so dramatically.

But if I have the walkabouts, some people have the flyabouts. Take Louise Varley, for instance, if you can catch her. At 60, she now lives in Chichester, England, but she’s also set up house in Mexico, Turkey, Sri Lanka and Trinidad. And those are just the places that came up in a short conversation, along with her sporting interests over the years, such as diving, fencing and skiing. Like me, she too took to the water.

“I met someone in Trinidad and went off to sail around the world,” she says, as if she had simply hitched a ride to the supermarket and back. Her two years of sailing on a 36-foot boat included an entire circumnavigation of the globe.

But the adventurous spirit doesn’t always exhibit itself so dramatically. It can be expressed in other ways, like trying every sports fad that comes along, making perpetual career changes, or collecting exotic flowers.

Do we adventurers exist to those who study the human mind?

And sometimes it springs up in a surprisingly daring way, like Martha Enson, the 50-year-old performer in Seattle. She calls herself a theater performer, creator and producer, but what she really does are gravity- and death-defying aerial acrobatics up in the air — on ropes.

“I think of being adventurous as being scared and then leaning into it,” Martha says. “If I don’t know where I’m going, and I’m excited to go there, that’s an adventure!”

But where does this spirit of adventure originate? Do we adventurers exist to those who study the human mind?

It turns out that we do, according to Art Markman, Ph.D. and professor in Psychology and Marketing at The University of Texas at Austin.

“A personality characteristic called ‘openness to experience’ tells you how much you value trying new things, anything from traveling the world to testing the latest restaurant,” Dr. Markman said in a phone interview.

As the only wanderer in a family of deep-rooted oaks, all still planted within five miles of home, I asked Dr. Markman if this openness to experience is a virus I caught in childhood or if it’s hidden somewhere far back in my gene pool.

“Personality characteristics in general and openness to experience specifically have strong genetic components,” says Dr. Markman. “Environment does not have a huge impact.”

It’s not so easy to picture what the 70- or 80-year-old adventurer looks like.

This genetic gift of openness to experience is one of the so-called Big Five Personality Traits that some researchers believe are the broad categories making up our temperaments. The Big Five — openness, extraversion, agreeableness, conscientiousness and neuroticism — are the main ingredients in our personality recipe, and we all have differing measurements of each. A quick Web search will reveal a dozen online quizzes to measure your personal recipe.

“Parents who try to dampen their little daredevil end up just encouraging it,” he said.

While it’s easy to envision the stereotypical 25-year-old adventurer armed with a backpack and a sleeping bag, it’s not so easy to picture what the 70- or 80-year-old adventurer looks like.

“The openness will linger, but it will be less likely to be base jumping,” Dr. Markman says. “You still might travel the world when you’re old, but skip the whitewater rafting.”

Martha the acrobat plans to practice her physical derring-do as long as it feels right.

“If it’s thrilling, do it!” she says. “Why do you want to be doing mundane things?”

Louise’s wanderlust seems well intact.

“There are trips I haven’t done yet,” she says. “I’ve never been to Africa, so that’s a gap I’ve got to fill.”

She also wants to go to the Far East and would love to go diving again.

“Oh, I’ve thought of something else!” she says. “I’m learning to ride a motorbike.”

And as for me, my willow tree wanderlust still keeps me moving, but I’m flirting with land for a while, content to spend a month in Paris, four months in Annapolis, two months on Seattle’s beautiful Vashon Island.

And what’s next? Look, there’s an island on the horizon!