Phelps is more than that, though. He has transcended his sport, moving quickly from a playful childhood around Maryland pool decks to his well-deserved status as a global icon, the crown of the Greatest Olympian of All-Time specially fit just for him.
Over nine days in China, the water rippled from the Water Cube all across the world. It's difficult to imagine anyone ever again winning eight gold medals at a single Olympics. But that doesn't fully explain why Phelps' story and his accomplishments were so special.
There are many reasons Phelps is different from the rest, but there's just one explanation that connects all the dots. Phelps explained it himself after he won his eighth and final gold: "It's just a dream come true."
Not in a passive sense, though. He made it come true. Phelps' secret is that he dreams with his eyes wide open.
For years, he kept a list of goals on his nightstand. Impossible swimming times. Ridiculous ambitions. Hopes that only a mad man might aspire to. Or a great one.
The list was there every night when he went to sleep. And there every morning when he awoke. His world has no boundaries separating the fantasy from the reasonable.
"Every day it seems like I'm in sort of a dream world," Phelps had said in the midst of the Games. "Sometimes you sort of have to pinch yourself to see if it's really real."
It was. The world can attest to that. And his Beijing trip followed that bedside script almost perfectly.
Phelps wasn't just living his own dream, though. He was swimming through everybody's. When he dived into the water, he took us with him. When he made a turn, so did our stomachs. And when he stretched his arms for the final wall, we stretched ours to the heavens.
Each race and each day produced unforgettable moments, the kinds of memories that don't yellow with age. Phelps had a starring role in an eight-part serial packed with drama, emotion and superhuman exploits.
He brought the pool water to a boil in his opening race, finishing miles ahead of his competition in the 400-meter individual medley. The next day, he showed just how much emotion and energy he had stored up for these Games, exploding in celebration after the 400 freestyle relay win. He picked up gold medals Nos. 4 and 5 by tackling two finals within 90 minutes of each other. In fact, in the fourth final, the 200 fly, he glided to victory even though his goggles had filled with water and he couldn't see the wall at race's end.
His seventh gold was perhaps the most exciting, as Phelps trailed for almost all of the 100 butterfly. He appeared to hit the wall second, out-touched by Milorad Cavic. But as Cavic glided beneath the water, Phelps instinctively took an extra half stroke atop it, winning gold by 0.01 of a second.
"Honestly, even after he won the seventh gold medal there was just something in my head," said his coach, Bob Bowman. "I kept telling myself, you know, this isn't going to happen. We've had too good of luck."
Luck was never a factor. Phelps made that clear in his final race. Swimming the third leg in the 400 medley relay, Phelps dived into the pool with the United States trailing in third place. By time he pulled himself out, his team was in first. He had given the team a lead it would hold until the end.
The superlatives came from all angles, no compliment embellished and no assessment unfounded. But it was Phelps himself who found the perfect words. He understood better than anyone else how this all came to be. "If you dream as big as you can dream," he said, "anything is possible." And there it is. As perfect as it is succinct. The TV cameras had no clue, but that was the secret. To achieve, we must dream.
It's what connects great thinkers, believers and doers from all walks of life. It's how the Colts won in 1958, how a kid from Aberdeen grew up to play 2,632 baseball games in a row. How boys and girls of all ages, from all walks of life and from all corners of the planet overcome their surroundings to make themselves better.
And in turn, they make us all better. Ability and opportunity might vary, but we can all close our eyes and dream. The key is opening them and living out that dream.
Phelps will undoubtedly create a new list and new goals, but his accomplishments at the Beijing Games will endure. He didn't simply win eight gold medals; he showed that he truly has the Midas touch. And in the summer of 2008, not a soul could avoid it. He touched us all.
What's your dream? Is it a secret between you and the pillow or something you carry with you day-to-day, nurturing with all the time and energy you can muster?
Eight gold medals? That was never really the point.
"I think it really shows that no matter what you set your imagination to, anything can happen," Phelps said.
He made his dream come true, the instructions deceptively simple: Just add water.
But he reminds all of us that we can do it, too. This makes him not a great swimmer and not an Olympic god but something much bigger. Baltimore's son is the world's best envoy. Through him, we all dream and we're all made of gold.