One of the first times Charley Johnson  decided to “pay it forward,” he bought a coffee and a doughnut for a guy at a gas station. It cost something like $1.75. Then he handed the guy a bracelet that said “Pay It Forward.” Charley didn’t come from a family with money. He made his own money running a manufacturing company where he had worked since he was 15 years old. At age 30, he had the fancy car he wanted as a kid and the house of his dreams in Salt Lake City. “I had everything,” he says, “but one day I was sitting on the edge of my bed and realized, ‘I’m not happy.’ ”

He wanted to do something better for the world and flashed on the idea of a bracelet — one like the Livestrong cancer bracelets, but this one to remind people to pay forward a good deed. Charley hoped the guy at the gas station would do a favor for someone else — and pass on the bracelet, too, as a reminder for them to pay it forward.

The idea caught on. Charley started making tens of thousands of Pay It Forward bracelets. In Koprivnica, Croatia, Katarina Pavlek saw the movie Pay It Forward and tracked down Charley online to get her dance students involved in the movement. In Canada, Michael Whelton, a school principal, was inspired by the movie and reached out to Charley for ideas of how to make St. John, New Brunswick, the “kindest city” in the country. In 2012, Charley traveled to 15 countries, handing out bracelets through the nonprofit Pay It Forward Foundation in San Luis Obispo, Calif. So far, he’s distributed 2.4 million bracelets in 132 countries from Afghanistan to Zambia. “I don’t want to change the world,” he likes to say, “just make it nicer.”

The concept of paying a kindness forward has been around at least since biblical times. In ancient Athens, the playwright Menander used the idea in a comedy about a grouchy Greek father unwilling to share his good fortune. Benjamin Franklin touted the pay-it-forward idea in the 18th century; Ralph Waldo Emerson in the 19th century. In 2000, Catherine Ryan Hyde added a new twist in her novel Pay It Forward about a 12-year-old boy with an assignment to make the world a better place. The idea? Do a kind act for three people and ask each of them to pay it forward to three more people. “I didn’t invent kindness,” Catherine says. “Good Samaritans exist in the Bible, but what Pay It Forward added was the exponential math.”

It’s more than doing something nice for someone. It’s making sure the idea spreads, she says. Haley Joel Osment, who starred in the movie Pay It Forward when he was 12, nailed the idea when I interviewed him for a story in Time magazine by saying: “Three becomes nine, and nine becomes 27, and so on, like a chain. I’ve done the math, and you can reach millions, billions of people, all paying it forward.”

Even before the book, Catherine paid it forward, repairing old trucks and giving them free to those who couldn’t afford them. As founder of the Pay It Forward Foundation, she’s no longer shocked when she hears amazing stories about people paying it forward. “You can’t spend 24 hours a day being blown away,” she says. “At some point, you have to do the laundry.” She has written more than 20 books, including two best-sellers, but she says she is not interested in writing a sequel to Pay It Forward. “I don’t have it in me to milk it,” she says. But with schools adopting the pay-it-forward idea, she decided she will release a shorter version later this year for the 8-to-12-year-old crowd.

Charley Johnson, who saw the movie at age 20, is now 33 and still tormenting himself. No wonder. His goal, as president of the Pay It Forward Foundation (he gets no paycheck), is to reach 7.1 billion people — the world’s population — with the idea. “Tens of millions of people want to make the world better and they don’t know what to do. This movement is exciting to them because they get involved immediately,” he says. “It’s an interaction between two people, just a split second, and it goes to someone else and someone else and someone else. The chain doesn’t break.”

Unrealistic? Nope. “We’re going to change the mindset of billions of people,” he says. And he’s looking for new ways to reach those countries that do not have Pay It Forward bracelets. To those who want to distribute them, they can be purchased at the Pay It Forward Experience website. So if you’re going to Bolivia or Laos or even Vatican City — where there are no bracelets — contact Charley at the Pay It Forward Experience and pay it forward, as he did.