When you're the winning-est winner of all, why do you want to go back and compete again?
Swimming superstar Michael Phelps gives a simple answer: "It's fun."
Twenty months ago, after hanging his 18th medal around his neck at the London Olympics, Phelps climbed out of the pool, which he would later describe as a "place of obligation."
Since then, fun-loving Phelps has been pictured at golf tournaments, at well-known night spots and with celebrities of various sorts.
This week, however, after plopping on his cap, the blue and white North Baltimore Aquatic Club headgear, Phelps showed up at the front of the pack.
Will this splash in the pool in Mesa, Arizona, followed by dozens more, lead to the first place box at the next Olympics?
Perhaps ... perhaps not.
Other champions have tried that route.
Record books tell us that world heavyweight champion George Foreman staged a comeback after 10 years.
He lost twice.
Continuing to make grills might have been easier.
Foreman persisted, however, and finally regained the boxing crown he had won 20 years before.
Basketball, too, has a famous comeback kid.
Michael Jordan is described as the world's greatest basketball player. He retired at the height of his game and pursued baseball.
Although he hadn't played baseball since his teens, he did compete successfully in minor leagues. He never, however, approached Willie Mays' records in the outfield.
No matter.
Jordan returned to basketball and won an NBA title.
So what's the guess about Michael Phelps?
Comebacks are as chancy as are the original careers.
Phelps, however, says that he loves swimming, loves being in the water and hanging around at the pool.
Following this recent race, Phelps commented that he was as excited as he was when, as a ten-year old, he hit the water for his first race.
Will the fun and excitement continue or will "been there, done that" be Phelps' mantra?
Stay tuned.