Dara Torres was 41 when she won three silver medals at the 2008 Beijing Olympics, a mothering figure to Michael Phelps and the other United States swimmers. She tried, and failed, to make the U.S. team for London at the age of 45. So Torres knows the feeling of being an aging swimmer seeking another dip in the Olympic pool, and she thinks Phelps will one day, too.
On Sunday, hours after Phelps won what he swears will be his last competitive race, Torres was on Twitter betting that the winningest Olympian ever wouldn't stay retired.
"Anyone care to wager???" Torres wrote.
One of the replies came from Phelps himself. He took the bet.
Anthony Ervin, the U.S. swimmer who sold his 2000 gold medal to aid victims of the Indian Ocean tsunami, then came out of retirement after nine years to make the 2012 team, tweeted that if Phelps doesn't come back, "I'll eat my fins."
You can never be too sure about these things, of course, but I'd wager Torres and Ervin will eat their words.
I think Phelps will stay away from the pool despite the long history of athletes who've seen the other side of the retirement wall and decided to throw their caps back over.
Brett Favre bounced back and forth from retirement to the point of becoming a national distraction and there have been others. George Foreman came back to win a heavyweight title at 45.
But Phelps, while speaking late Saturday night after swimming the butterfly leg for the winning U.S. 400-meter medley relay team, sounded like a man who was tired of the whole thing after 22 medals, 18 of them gold -- both Olympic records.
He seemed tired of the training, of the races, of us. Of all of it.
Phelps has been swimming since he was six and working on all four strokes with his coach Bob Bowman since he was 11. He has faced the pressure of being the face of swimming since he was 19.
That last one, actually, is something he relishes; one of Phelps' long-term goals has always been to grow the sport. But at 27, he can help in other ways, like through his foundation.
"I'm not really sure how to put everything into words yet," he said. "It's wild. Twenty years. I couldn't ask to finish on a better note. I've done everything I've ever wanted to do and I'm very happy."
And then he trailed off.
"I don't know," he laughed. "That's about all I got for you guys right now."
Phelps has always said he'd walk away before the age of 30. Like Lorena Ochoa, he has eyed an early retirement despite the wishes of those who might like to see him stick around for another year.
But, Phelps said, he knows one year means two years means three years means another Olympics, and that's just not in his plans. Rio 2016 will have to do with the likes of current teenagers Missy Franklin and Katie Ledecky, and Phelps' U.S. teammate and rival Ryan Lochte, if he continues to swim at a high level.
"I'm ready to be done. I'm ready to retire and move on to other things," said Phelps. "I'm very satisfied. I'm very happy with it, kind of relaxed now. Kind of weird. I'm a lot more relaxed than I thought I would be in this moment. I thought I would be a lot more emotional, but I'm just not right now. It'll probably hit me hard these next couple of days."
He would like to see things, experience new places. Europe, maybe. And he wants to cage dive with sharks, something he's already talked about with Chad le Clos, the 20-year-old South African who beat his hero in the men's 200 fly here.
Funny, you say, that someone who has competed in countries around the world would want to travel. But think about the life of a swimmer: races in the morning, more at night, and off to bed. Athletes like Phelps rarely see more than the pool and their hotel. So, in a way, he's never really been anywhere. Every trip is the same.
"I'd like to just experience things," Phelps said.
He explained: "I've always been a very goal-oriented person. I think after this, whatever route I go down I'm going to have goals in whatever I do. I'm still a very competitive person.
"If I go out and practice golf, I'm going to want to drop X amount of strokes. I'm going to have things that I'll be able to go for and try to achieve."
And plenty of time to do it, if you believe him.