Before Michael Phelps won 22 Olympic medals, before he became the world’s most famous swimmer and a global celebrity, he stood on a pool deck in Minneapolis and gawked. The skinny boy from Baltimore raced in his first national-championship meet at the University Aquatic Center in 1999 — and finished dead last in two events, as coach Bob Bowman teasingly reminded him Wednesday.

Over the years, Phelps drifted far away from that 14-year-old dreamer, even as he piled up 18 Olympic golds. But after emerging from what he called “the darkest place of my life,” Phelps returned to the U pool this week fully immersed in a career revival aimed at the 2016 Rio Olympics.

The most decorated Olympian in history, Phelps, 30, is entered in six events at the Arena Pro Swim Series meet. As he began competition Thursday, finishing third in the 100-meter butterfly and 10th in the 200 freestyle, he bubbled with the same enthusiasm and ambition he felt during his first time in Minneapolis.

“I just have so much that I truly still want to accomplish,” he said. “I’m not going to have a ‘what-if’ in this sport. I’m going to walk out how I want to walk out.”

Phelps took his psychic burdens public in a Sports Illustrated cover story this week, describing how he was “not wanting to be alive anymore” after an arrest for drunken driving in September 2014. A six-week stay at a treatment facility helped the four-time Olympian uncover a happy, healthy and highly focused athlete who is not ready to relinquish his place on the world stage.

Last August, after Phelps was barred from competing in the world championships as punishment for his arrest, he demonstrated what he can do when fully committed. He swam the fastest times in the world this year in the 100- and 200-meter butterfly and the 200 individual medley at the U.S. championships, clocking some of the best performances of a glittering career.

At first, Phelps said, he was a bit surprised at those times. With his life on increasingly solid ground outside the water, he is more motivated than ever to see how much lower they can go.

“Anything is possible,” said Phelps, who is scheduled to race in the 200 butterfly and 100 backstroke on Friday and the 200 individual medley and 100 freestyle on Saturday. “I do believe there is still more in the tank, and it’s just up to Bob and I to find out how to get there.

“I am 30, but who cares? I’m hungrier now than I was leading into 2012. I feel like I did in high school, that kind of excitement level. I’m thrilled to be going into this year and kind of giddy to see what happens at the end.”

This week’s races will give Phelps a chance to gauge how much he has progressed since the August championships. The meet is an early step in his race toward Rio — he is competing with a full beard and working on fine-tuning his technique — but he will face many of the top swimmers in the nation, as well as some international competitors, in a meet that unofficially begins the Olympic season.

Since his arrest last year, Phelps has adopted a healthier diet, stopped drinking alcohol, gotten engaged and repaired his relationships with his father and with Bowman. At the nationals in August, he swam a time of 50.45 seconds in the 100 fly, 1 minute, 52.94 seconds in the 200 fly and 1:54.75 in the 200 IM. That propped up his confidence, which had sagged under the weight of his personal struggles.

Phelps admitted Wednesday he was just “going through the motions” between 2008, when he broke Mark Spitz’s record by winning eight gold medals at the Beijing Olympics, and 2012, when his six-medal performance at the London Games gave him a record 22 Olympic medals for his career. Bowman recalled how he felt sick to his stomach every day when he arrived at the pool during the run-up to the 2012 Olympics, wondering whether Phelps would even show up for training sessions.

“I’d start watching the clock,” Bowman said. “I’d start pacing around. Is he coming? Is he not coming? It was a struggle.

“Now, he’s the first one there. It’s been great.”

Phelps said that back then, he felt like he was forced to continue swimming. Before he could determine whether he had any desire left in his heart, he had to reach a better understanding of himself as a person.

The therapy he underwent during his time in treatment last year renewed his spirit and restored his love for the water. Though he believes he is capable of lowering his personal-best times, Phelps stressed that a 30-year-old body requires much more care than a 20-year-old one. He has had to accept that it takes longer to recover from strenuous swims, and good nutrition and more sleep are mandatory.

None of those things feel like sacrifices, though. His performances at the nationals in August pushed Phelps to be even more diligent during workouts at his Arizona training base, and he could not stop smiling Wednesday as he pondered where his new commitment might lead.

One thing has not changed. Phelps declined to reveal his goals for the upcoming year, beyond making the Olympic team; those always have been a secret between him and Bowman. But he promised they are “very big and exciting” — kind of like life itself, now that the water is once again clear.

“I don’t have anything to hide,” Phelps said. “I’m a human being. Everything’s out there. I am how I am; that’s how I live my life now. And I’m so much happier.”