Michael Phelps had barely finished swimming what he promised would be his final race than the questions started: At a post-race news conference, a reporter asked his 400 Medley Relay mates, Matt Grevers, Brendan Hansen and Nathan Adrian: did they believe Phelps was really leaving the sport? Before any of them could answer, Phelps broke in. “Yes!” he said, and then was gone.

He had long said London would be his swan song and we should believe him. The question is asked partly because, in recent years, so many other aging swimmers have returned from ‘retirement’—Brendan Hansen being one. But their circumstances are nothing like Phelps’s.

For one thing, a USA swimmer with potential to reach an Olympic final can earn $100,000+ per year in stipends from USA Swimming and swim apparel sponsorship. In today’s job market, how many 20-somethings can find ‘serious’ jobs which pay that well?  But Phelps is estimated to have banked up to $50 million since turning professional when he signed an endorsement contract with Speedo at age 16.

For another, no other swimmer in history has ever borne as heavy a burden of expectation or responsibility. And, in a sense, he’s borne outsize expectations since age 11.  Phelps joined the North Baltimore Aquatic Club team at age 7, mainly because his older sisters, Whitney and Hilary, were on the team and he had to tag along to the pool when they went to practice.  (Whitney was the top-ranked American woman in the 200 butterfly in 1996 before a back injury forced her retirement from swimming.) NBAC , perhaps the most successful swimming club of all time, produced three Olympic gold medalists–Theresa Andrews, Anita Nall and Beth Botsford–before Phelps.

When Phelps was 11, Bob Bowman the new NBAC coach, told his parents that their gangly, hyper-active son—sometimes described as ‘goofy’–had the talent to become the world’s greatest swimmer, and that to fulfill his promise he needed to leave behind his peers and swim with the club’s elite training group, sharing a lane with swimmers as old as 18, every day — and before long, twice a day.

Excepting that he continued to sleep in his own bed and eat his mom’s cooking, his life since is not entirely unlike those of promising Chinese athletes taken from their families and shipped to sport factories in adolescence. As Bowman has acknowledged, Michael had to sacrifice many aspects of a ‘normal childhood’ since being set on that path.

What 11-year old wouldn’t be starry-eyed at the prospect of being the world’s greatest anything—but can any 11-year old really understand all that he or she is signing on for? Not just the idea that one day you might hang out with Lebron (though Lebron wasn’t yet “The Chosen One” in 1996) and David Beckham—but living the life of an aquatic monk, while your friends play video games and hang out.

How many of us—offered that bargain–wouldn’t grab it in a heartbeat? Still, once you became ‘the greatest swimmer in the world,’ wouldn’t you yearn to live a ‘normal’ life? (Especially if, as seems true of Phelps, you’re naturally more inclined to being a relatively private person.) So it was already remarkable that he stayed in the sport four more years after Beijing to bid us farewell in London.

As we now know Phelps did become the greatest swimmer of all time. He made an Olympic final, in Sydney in 200-meter butterfly, at 15, an age when most male swimmers—even those destined to be an Olympic finalist in their 20s—are fortunate to qualify for the US Junior Nationals.  The next spring, still 15, he became the youngest male swimmer ever to hold a world record, also in the 200 fly.

In the next two years, he set 10 more world records in four individual events (plus a relay), after which he and Bowman announced he would try to match or break Mark Spitz’s record of 7 Olympic gold medals the next year in Athens. Upon which, Speedo announced they would pay him a $1 million bounty if he did. In the end, he had only the second-greatest Olympic medal haul in history, winning six gold and two bronze. This immediately raised the stakes for Beijing four years hence.

How many, not yet in their 20s, have ever been the subject of intense global expectation, examination, and speculation? For over 10 years, he’s been expected to lead USA Swimming to worldwide dominance—and win public attention for an entire sport; to provide a return on the investments of Speedo, Visa, AT&T Wireless, Omega watches, Argent Mortgage, and Procter & Gamble, among others; swim the million meters a year it took to fend off would-be challengers;–and finally to win those eight races in Beijing, two of them by vanishingly thin margins.

Phelps was truly one of a kind. To my mind the physical gifts that gave him the opportunity to be the best swimmer of all time, are less impressive than the strength of his psyche–without which he could not have shouldered the weight of all those expectations, nor ever fall short in the pool when it really mattered. Of the dozens of lavishly talented swimmers, who have passed through the sport in the 44 years since I first followed Olympic swimming in 1968. Phelps is the first I can recall who rose to the occasion every single time.

So as amazing as it may look from the outside to be Michael Phelps—the greatest athlete on the biggest stage and immensely wealthy in the bargain– none of us should forget it’s a job, and one he’s performed with unequaled excellence.  Don’t you think he’s earned at least 10 years of quiet, contemplative relaxation, if that should be his preference?