He wanted to be one of those rare athletes who went out on top.
“That's just who he is,” said Bob Bowman, his longtime coach. “He just couldn't live with himself if knew he didn't go out there and give it good shot and really know he's competitive. He doesn't know anything else but to give that kind of effort and have those kind of expectations.”
Phelps got off to a rocky start in London, finishing fourth in the 400-meter individual medley, blown out of the water by his friend and rival, Ryan Lochte. It was only the second time that Phelps had not at least finished in the top three of an Olympic race, the first coming way back in 2000 when he was fifth in his only event of the Sydney Games as a 15-year-old.
To everyone looking in, Lochte seemed poised to become the new Phelps — while the real Phelps appeared all washed up.
But he wasn't going out like that.
Phelps rebounded to become the biggest star at the pool, edging Lochte in the 200 IM, contributing to a pair of relay victories, and winning his final individual race, the 100 butterfly. There were two silvers, as well, leaving Phelps with a staggering resume that will be awfully difficult for anyone to eclipse.
His 18 golds are twice as many as anyone else in Olympic history. His 22 medals are four clear of Larisa Latynina, a Soviet-era gymnast, and seven more than the next athlete on the list. Heck, if Phelps was a nation, he'd be 58th in the medal standings, just one behind India (population: 1.2 billion).
“When I'm flying all over the place, I write a lot in my journal,” Phelps said. “I kind of relive all the memories, all the moments I had throughout my career. That's pretty special. I've never done that before. It's amazing when you see it all on paper.”
Four months into retirement, Phelps has no desire to get back in the pool. Oh, he'll swim every now and then for relaxation, using the water to unwind rather than putting in one of his famously grueling practices. Golf is his passion at the moment, but he's also found time to cheer on his hometown NFL team, the Baltimore Ravens, and start looking around for a racehorse that he and Bowman can buy together.
Phelps hasn't turned his back on swimming, either. He's got his name attached to a line of schools that he wants to take worldwide. He's also devoting more time to his foundation, which is dedicated to teaching kids to swim and funding programs that will grow the sport even more.
He's already done so much.
“His contribution to the way the world thinks about swimming is so powerful,” Bowman said. “I don't think any other athlete has transformed his sport the way he's transformed swimming.”
Phelps still receives regular texts from old friends and teammates, asking when he's going to give up on this retirement thing and come back the pool as a competitor.
He scoffs at the notion, sounding more sure of himself now than he did in London.
And if there's anything we've learned: Don't doubt Michael Phelps when he sets his mind on something.
“Sure, I could come back in another four years. But why?” he asked, not waiting for an answer. “I've done everything I wanted to do. There's no point in coming back.”