(CNN) -- In 2002, at the ages of 62 and 48, Pat and Catherine Patterson decided to leave it all behind. They sold their real estate business and their cars, gave their furniture to their children, and put their home up for rent. Strapping their remaining possessions to two bicycles, the couple set off to bike around the world.
Pat and Cat Patterson wave from the white beaches of Zanzibar, an island off the east coast of Africa.
Fifty-seven countries, four continents and almost four years later, the Pattersons look back on their journey as something no less than life-changing.
In 1985, Pat Patterson got his first taste of freedom behind the handlebars of a bicycle when he went on a short tour through China. The trip changed his perspective. "I was beginning to see things differently," he says.
One day, Patterson and his fellow bikers pulled into a village for lunch, and soon found themselves surrounded by curious locals. One boy, around 14 or 15, hovered especially close to Pat and they exchanged hellos in their own pidgin version of the other's language.
"We started having this little, best-we-could conversation, and it lasted a couple of minutes. He was trying to get inside my mind, and see what it was like where I came from. And I was trying to get inside his and see what it was like for him, living where he lives. From that minute, I thought, this would be a great way to travel."
By the end of his trip to China, Pat was ready to dispense with the guides and the tour group and pursue on his own what he refers to as his "insanity," that is, bike touring through foreign countries. See a map of Pat and Cat's journey, complete with videos »
In 1993 Pat met Catherine. The two fell in love, got married and bought a real estate company together. Catherine, or Cat, as he calls her, started helping Pat compile his photos from his bicycling trip in China, and another trip he had taken a couple years later. The photos piqued her curiosity, and she suggested they plan a trip together.
Then, in 2000, Catherine suffered a heart attack. "At first we thought, 'Well, that's it for the trip,' " says Pat, but eventually Cat's heart attack only heightened the couple's desire to get biking. Pat says, "It makes you realize you don't have forever. By 2001, I was looking for someone to buy the company."
Soon, they found a buyer and the preparations began. "It's funny, I guess I'm just one of those types of person that got on board with the idea," says Catherine. She says the hardest part of the journey was telling her parents, each in their 80s, that she would be gone for so long. But she bought them a laptop and taught them to use it, and kept in close contact through e-mail.
The Pattersons sold their company, their house and their cars and gave all their furniture to their children. They bought a new home and rented it out. The day they left, their co-workers at the real estate company gathered for a send-off party.
"Pedaling away from our real estate firm," Catherine says, "With all of our friends gathered, waving, saying 'Goodbye! You're crazy!' I felt like the weight of the world lifted off my shoulders."
Between 2002 and 2006, the Pattersons biked from California east across the United States to Greenland, through Europe and Russia, down Africa, then from southern Chile all the way back up to California. See photos from the couple's trip »
They biked about 50 miles every day, which Pat says, "Isn't a lot if that's all you do." They stayed in hotels most of the time, for the sake of safety and comfort, but they biked with camping supplies in case the need arose. They planned their routes using only maps and Lonely Planet travel guides. They assessed the safety of their surroundings by talking with locals. "Gather a consensus of opinion; ask three times. Ask, ask, ask -- we did," Pat says.
The trip wasn't seamless. They were robbed of their computers once, and another time they were held up at gunpoint. In Finland, it was so cold they eventually had to give up biking and fly down to warmer weather in Portugal.
"I never in my wildest dreams thought that I would do something like that in my life," Cat confesses. "I think you just have to be open-minded and willing to take chances and risks and not be afraid. ... You just have to open your mind to other cultures and countries and, you know, like Pat says, 98 percent of the people in this world are good people. On a day-to-day basis you're meeting the average person in the world and they're just like you."
Pat tells a story about a border crossing between Guinea-Bissau and Guinea-Conakry, on the west coast of Africa. A border patrol agent got tough with the Pattersons, asking them to unpack all their bags, follow him into a small building and leave their belongings outside. The Pattersons refused. Finally Pat handed his passport over to the agent who took one look at it and said "1939?"
"Yes," Pat replied, "I was born in 1939."
The border patrol agent sent a young boy running off into the nearby village and he soon returned leading an old man behind him. The border patrol agent introduced the old man to Pat, saying, "Oldest man in village, 1939."
"And now we're all brothers, we're hugging, shaking hands, and we didn't have to open the bags." Pat and Cat both say it was these experiences that kept them inspired and encouraged on their route.
Pat says that, more than anything, biking around the world has changed what he values in life. Pat admits that when he was in his 30s his philosophy could be summed up as, "The one that dies with the most money wins." But, once he started making money, he realized he had to find a way to spend it. By the time he reached his 40s, his philosophy had become, "The one that dies with the most toys wins."
"So, I had the cars and the things," Pat explains, "and then, about that time, I took off out into the world on my own for a bike ride, and decided it was experiences; the one that dies with the most experiences wins."
As Pat was preparing for his trip with Catherine, he turned 60. He calls that birthday, and the change in mindset it brought, "a biggie." His philosophy became, "The one that dies with the most friends wins."
"I'm realizing what it's going to be in my 70s, and that's different. It will be 'The one with the most memories wins.' "
For her part, Catherine says, simply, "As with most things in life, the most difficult things make the best memories."
The couple is not done; they plan to start a cycling trip across Asia in November 2008. E-mail to a friend