Michael Phelps reflective and content having concluded the greatest career in swimming

When Michael Phelps opened the door to his hotel room in the early hours of Sunday morning, he did the worst thing possible to his slumbering fiancee, Nicole Johnson.

He picked up their 3-month-old son, Boomer, and woke him with a hug.

Phelps just had to do it after spending so much time away from his firstborn in preparation for the Rio Olympics. The most decorated medalist in history even changed a diaper.

Phelps awoke Sunday morning, the day after what he says was the last race of his career, as a contented man. He stared at all six medals — five gold and one silver — he won at these Games. And he felt, once again, that he’d done everything he possibly could in the sport that’s dominated his life since he was 7 years old.

“I was happy,” he said. “I was happy with the way my career ended. And I couldn’t say that about London” four years ago.

Phelps spent most of Saturday evening on the verge of tears as he prepared for his final race with his coach of 20 years, Bob Bowman. They didn’t say much, but Bowman walked beside him through every stroke of his warmup swim.

“He knew last night was the last one,” Phelps said, referring to the 400-meter medley relay. “I think that’s why it was so special for both of us. We knew what we had been through, and we knew it was coming to an end.”

Bowman said he’d be a fool to expect another swimmer of the same quality to enter his life.

“I’m not even looking,” Bowman said. “He’s too special. It’s not even once in a generation. It might be once in 10 generations that someone like Michael comes along. He had the physical skills, the mental outlook, the family that supported swimming. He was in a great swimming club. He has an emotional ability to get up for big races and actually perform better under pressure. So I don’t think you’re going to be seeing Michael. But you’re going to be seeing a lot of other wonderful people.”

Phelps led a U.S. team that outperformed expectations and turned the page toward a promising future without its most enduring star.

The United States won 33 overall medals, 23 more than second-place Australia, and 16 gold medals, 13 more than any other country. The medal count was up two from 2012.

“It seemed like pretty much every race, we had somebody up on that podium,” Phelps said.

Aside from Phelps, many of the top stars plan to continue swimming through the 2020 Games in Tokyo.

Katie Ledecky, 19, leads the pack after living up to outlandish expectations by winning four gold medals and smashing two world records.

She will begin her freshman year at Stanford when she gets home and will swim for the Cardinal. She said she hasn’t set her goals for 2020 but assured reporters they would be ambitious.

Ledecky was a sure thing. More uplifting were surprise star turns from first-time Olympians Simone Manuel, Lilly King and Ryan Murphy, among others.

Before the U.S. team could move on to its encouraging future, it said goodbye — if tentatively, given many of the younger swimmers’ hopes that Phelps will unretire again — to its greatest star.

Phelps didn’t offer too many specifics about how he will occupy himself in the months to come. He will work as an unpaid assistant to Bowman, who coaches at Arizona State. He and Johnson plan to marry toward the end of the year and remain in Arizona for at least a few years.

“It’s great for us to be in a new area and start a fresh family, a new family,” he said. “But Baltimore’s for life for me. … That is my home. That’s where I grew up. That’s where I learned to swim.”

Phelps revealed that he’s learned to lull Boomer to sleep by dangling his medals back and forth. And he might even let his firstborn take one into school for show and tell some day.

“I might have to go with him and take every step with him.” Phelps joked.

Only two or three people know where he keeps his medal stash, he added. But he’s looking forward to seeing all 28 together.

“Insane,” he said, an apt final verdict on his career.

childs.walker@baltsun.com