How sport can save the world
Towards the end of Ian Thorpe's swimming career, the Australian took a trip that would change him forever.
He visited parts of the world suffering from the most demeaning poverty, places where the inhabitants had almost no opportunities for escape or improvement and where diseases eradicated in the developed world still took a terrible toll.
It was a trip that shocked Thorpe because it was a journey to the heart of his own country and those inhabitants were fellow Australians. In fact, they were the original Australians.
I heard the 26-year-old tell this story at a conference last week called Beyond Sport, an apt title because sport has played a vital role in Thorpe's journey from Olympic hero to campaigner for aboriginal rights. But his story is about more than sport, or more than we usually assume sport can achieve.
Prodigiously talented, hard working and expertly coached, Thorpe was the Aussie dream personified.
At 14, he became the youngest male to swim for his country. At 15, he won his first two world championship golds. At 16, he set four individual long-course world records. At 17, the Sydneysider became a triple Olympic champion in his hometown.
The following year was even better. He won six golds at the 2001 Worlds, setting new records in his three individual races - the 200m, 400m and 800m freestyle - to lead Australia to its first medal-topping performance at a global swimming meet since 1956.
At this point it seemed certain "Thorpedo" and his size 17 feet would go on to emulate Mark Spitz's haul of seven golds at the 1972 Olympics. Already the finest middle-distance freestyler in history, he only needed to find one more event.
But it wasn't to be, and despite a last hurrah at the 2004 Olympics, where he famously resisted the rising challenge from a young American called Phelps to claim his fourth and fifth Olympic golds, illness, injury and a waning of the desire to put in those long hours in the pool led him to make an emotional farewell to swimming in 2006.
So what next?
Swimming great Ian Thorpe tells BBC Sport's Matt Slater about his work with aboriginal communities in Australia
"I knew what I didn't want to do but wasn't sure quite what I wanted to do, I'm still not sure now," Thorpe told me.
"But I've made a start and I've thrown myself into it. I get a lot of balance from the things I do around the world."
Balance is an intriguing word to use and it struck me that Thorpe has been looking for equilibrium from the first moment he came to the world's attention - he set up a charity to help disadvantaged children when he was only 17 himself.
"There is a tremendous need there," he explained. "There is a huge difference between the life expectancy of aboriginal people and that of non-indigenous Australians (almost 20 years, according to Oxfam).
"There are people in Australia who suffer from illnesses at the same rate as people in the developing world. Australia is a rich country so I don't find that acceptable. We have the means to fix these problems but it's not happening.
"We're talking about a story that should be on the front page of newspapers but it isn't. We're talking about incredible poverty, pain and despair."
He went on to explain how desperate the "health emergency" is in some of these communities and just how isolated they are from the rest of the population.
I must admit I had little idea just how awful the situation remained for many of Australia's aborigines. I thought apologies had been made, policies implemented and scars were starting to heal.
I was wrong. But, believes Thorpe, I was no more wrong than millions of Australians who don't know any aborigines, don't want to know any aborigines and think more than enough money has already been spent on their problems.
It is a perception Thorpe has dedicated himself to changing and if it means making a few waves, so be it. Sport has given him a platform and he's not about to waste it.
Another sportsman with something to say - and the conviction to back those words with deeds - is NBA great Dikembe Mutombo. The 7ft 2in star from the Democratic Republic of Congo was also at the conference and like Thorpe he had an incredible tale to tell.
Mutombo will not be a familiar name to many of you but he has been part of the furniture for US basketball fans for two decades. Having arrived at Washington DC's Georgetown University to study medicine (but speaking almost no English), it wasn't long before he was persuaded to give basketball a try.
Up until this point his sporting passions had been football and karate but within a few years he had graduated from college basketball to the NBA's All-Star team in his first season in the league with the Denver Nuggets.
Eighteen years, five more teams and a total of 3,289 blocked shots later, a 42-year-old Mutombo finally retired from the sport, famous, popular and wealthy.
But that is only half of the story because in his spare time he built a $30m hospital in Kinshasa. OK, he didn't dig the foundations and cement the bricks but he did drive the project through from beginning to end and shell out $15m from his own pocket.
NBA star Dikembe Mutombo explains why he built a hospital in the Democratic Republic of Congo
"I worked hard to become a success but I never forgot the place that made me. I knew I had to go back home and help my people," said Mutombo, who shared the conference stage with Tony Blair, Prince Faisal of Jordan and Unicef ambassador Lord Puttnam.
"Lots of people asked me why I had come back and others wondered if I was going to be one of those guys who only do the 'talky talky'. I said I'm not just 'talky talky', I'm here to make a difference."
The end result for his war-torn land was the first modern, well-equipped hospital for nearly 50 years.
In another parallel with Thorpe, Mutombo is not afraid to throw a few elbows pour encourager les autres.
"I've been in verbal fights about (philanthropy), even with my team-mates at the Houston Rockets (his most recent team)," Mutombo admitted.
"I've challenged Yao Ming, Tracy McGrady, Shane Battier - young men making good money - to give something back. Tracy went to Darfur to see how he could bring food there. I persuaded Yao Ming to start a foundation to help young people in China. I passed the torch to others."
And he's not done there. For his next miracle he will attempt to persuade the developed world to do more for sport in Africa than just mine for talented Africans. He believes the West has an "obligation" to do more than that.
"Sport stops violence," he said. "And it can be like a classroom for teaching youngsters, especially for things like HIV prevention. That disease has killed 25 million in Africa and left 50 million orphans.
"If we can get kids together playing basketball or soccer we can then tell them what they need to know to survive. We can change living conditions and give hope and we can do it now."
I know Thorpe and Mutombo aren't the only sports stars who give more than just a little bit back but they are among a select few who are not afraid to step where others fear to tread.
They also instinctively understand sport's unrivalled ability to improve lives and promote change. They have gone beyond sport in every sense.