BY THE TIME I got home from Tibet two months later, Addi was potty-trained and speaking in full sentences. The mountain that I failed to climb is still there—ice-coated and indifferent. It would always be there, but the moment when Addi put her first sentence together was gone, and I'd missed it. Like any anguished father, I brought back a stuffed panda bear that was bigger than she was, and she's been sleeping with it ever since.

When Sue and I decided to have children, we already knew that the adventurous life wasn't enough for either of us; on the other hand, we weren't about to give it up. When feasible, we figured, we'd bring our kids along. Addi was six months old when Sue and I bicycled across Europe with her. We took her, at 13 months, to Costa Rica. When she was three and her new little sister, Teal, was six months, we went deep into the hinterlands of Mexico, staying in two-dollar-a-night village huts and eating the fiery cantina food. To this day, the girls love Latin culture.

We traveled as a family to Nepal, Russia, Australia, Spain, and Thailand—whenever schedules and finances jibed. It was our way of taking home with us. Eric Jackson, the 2005 world freestyle kayaking champion, and his wife, Kristine, who manages the family kayak business, did something even more extreme.

In 1997 the couple and their two kids, seven-year-old Emily and four-year-old Dane, were living in suburban D.C. Eric, now 41, was running a kayak school on the Potomac but training in Colorado and traveling to compete all over the country. "I just couldn't take it anymore," Eric—E. J.—tells me by phone. "I wasn't seeing my kids or my wife, but my kayaking never suffered. I'm extremely selfish about my kayaking.

"Kristine suggested we move into an RV," he says. "It saved our marriage."

She placed a classified ad in The Washington Post, and in one weekend they sold everything they owned. "People came into our house and walked out with our TV, silverware, clothes, the sheets on our bed," E. J. recalls. When it was all gone, the Jackson family drove off in an RV with their kayaks and $7,000 in cash, traveling across North America from one put-in to the next and kayaking at least 30 new rivers a year.

"One of the things that fascinates me most about American culture is the readiness to move," observes Jonathan Raban, 63, winner of a National Book Critics Circle Award for his 1996 Bad Land: An American Romance and a British expat who has lived in the States since 1990. "Americans have this inborn readiness to turn themselves into exiles. They have become accustomed to living the temporary life."

For the Jacksons, the strategy worked. "It was a real breakthrough," says E. J. "Every morning the kids were right there, Kristine was right there, we were all together, 24/7."

Kristine home-schooled the kids, and E. J. competed and taught kayaking clinics to make ends meet. ("I went to the pawnshop plenty of times," he says.) They lived in an RV for five years before settling along the Caney Fork River in central Tennessee and starting Jackson Kayaks, now the fourth-largest manufacturer of whitewater kayaks in the country.

"This place has everything we need," E. J. says. "A high-volume river with year-round whitewater, warm weather, and a rural environment."

Even with its gorgeous mountains and huge skies and our extended family nearby, Wyoming doesn't have everything we need. That's why Sue and I and the girls head off on a trip or two a year. The rest of the time, when I leave, I leave alone.

But I'm not gone for months anymore. I'm no longer bicycling across entire continents or climbing 8,000-meter peaks. I've already learned what these expeditions can teach; besides, they take too much time. I've become a master at moving fast. Mount Cook in one day rather than four, McKinley or Aconcagua in nine days rather than 24. I immerse myself in the sticky liquid of another culture, then hightail it back home.

I was there when both Addi and Teal learned to walk. I taught them both how to ride bikes, how to build a snow cave and use a map and compass, poop in the woods and wipe with snow, climb rocks and canoe rivers. Small skills. They taught me how to see the colors and ants, how to swing with my head thrown back, how to listen and believe.

The truth is, if your kids don't change your life, you—and they—are completely missing out. If you choose to bring them into the world, children are the biggest adventure there is. You only hope you can find the strength and courage and grit and love to live up to the opportunity.