Michael Phelps speaks with the media during a news conference Wednesday morning, not long after it was announced that he will serve as the United States’ flag bearer during Opening Ceremonies Friday night. (Chris Graythen/Getty Images)

The question was about Michael Phelps’s newborn son Boomer, a subject that animates him more than any other these days, but the answer took a sharp turn and arrived with a thwack, like an errant hand slamming against a hard plastic lane line. This was to be the beginning of Phelps’s goodbye, the most decorated Olympian of all time holding court with the international media Wednesday, two days before Phelps would carry the American flag in his first Opening Ceremonies, at the start of his fifth and — by all accounts — final Olympics.

And then came this:

“To have our first-born be able to watch — I’ll say this just, in case I come back — my potential last Olympics. Just so you guys don’t beat me to death if I come back, I’m just going to say that: To have him watch the potential last races of my career is something I look forward to being able to share with him.”

With those words, a stunned murmur went up across the room. To Phelps’s right, his coach Bob Bowman, the longtime comedic foil in Phelps’s podium performances, rolled his eyes. And the Rio de Janeiro Olympics, at which no storyline was to be bigger than Phelps’s farewell to competitive swimming, was jolted out of its carefully pre-scripted trajectory.

They were only words, and words do not equal action, but they are words Phelps had not recently spoken. Ever since he decided in 2014 to come out of his last retirement, which followed the 2012 London Games, he had insisted the Rio Olympics would be his last, and this time there was no reason not to believe him. He is 31 now, a first-time father, a soon-to-be married man, a newly enlightened human who has rehabilitated both his dangerous impulses and his image. This was to be his farewell, period, and the serenity that has recently come over him stemmed in no small part from that knowledge.

“This has been the greatest two years of my life, for a lot of reasons,” Phelps said Wednesday, “and I wouldn’t change it.”

If something has recently changed to alter his retirement plans, Phelps, whose 18 gold and 22 overall medals are the most all time, didn’t stick around to reveal it. He was hustled off the stage after roughly 25 minutes of media questioning, and there was neither time nor opportunity for a follow-up.

As has often been the case with Phelps, it was left to Ryan Lochte, his longtime friend, rival and wingman, to provide context — and Lochte, who in 2012 correctly predicted Phelps’s latest comeback, only added fuel to the notion these would not be Phelps’s final Olympics, after all.

“Once you’ve felt that passion, that thrill of racing the top people in the world, and that goes away, you miss it really quick,” said Lochte, who turned 32 Wednesday and who is rooming with Phelps here. “And I think that’s why he came back: He missed it, and he wasn’t done accomplishing what he wanted to accomplish in the sport. And I don’t think he’ll be done after this one.”

It would only prove Phelps is human if he decided within the past 48 hours, since the U.S. Olympic swimming team arrived in Rio de Janeiro, that this was not a life he wanted to give up. He is the unquestioned rock star of these Olympics, the centerpiece of NBC’s broadcast, the single biggest target of selfie-stalking Olympians in the Athletes’ Village.

After Michael Phelps retired from swimming following the Olympic games in 2012, he was arrested for a second DUI in 2014 and entered a rehab facility in Arizona. Now, he is focused on training to make history and return to a fifth Olympics in Rio. (Jayne Orenstein/The Washington Post)

On Tuesday, the 555-member Team USA contingent selected him voted him its flag bearer in the Opening Ceremonies, an honor that left him, he said, in tears. In past years, he has skipped the festivities, preferring to save his energy for his most grueling event, the 400-meter individual medley, which always falls the following day. But this year, in a concession to age, he didn’t even try to qualify in the 400 IM, which gives him an extra day to recover before starting his Olympic program — which this year will feature no more than six events — Sunday.

“The things I’ve done in my career have started to set in over the last two years, more than they ever have,” he said. “This has to be one of the coolest things I’ve ever done. It’s a little challenging to put into words. It’s just a cool feeling and an amazing, amazing, amazing honor.”

An about-face on retirement for Phelps, obviously, would be a massive development for the next Olympic quadrennial, giving NBC an anchor for four more years of swimming coverage and promotions and ensuring Phelps’s outsize influence would be felt across USA Swimming for that same period.

The 2020 Tokyo Olympics are 48 months away. Who is ready to say definitively that Michael Phelps won’t be there?