Heading into the 2016 Rio Olympics, Michael Phelps stood at a crossroads. His professional swimming career was winding down, and his parenting career had just begun. So did his life as a husband. Before the Games, Phelps secretly married longtime on-again, off-again girlfriend Nicole Johnson, and a month before that, the couple welcomed their first child, Boomer, to the world.

At Rio, Nicole and Boomer remained front and center -- commanding the attention as the cutest family at the Olympics -- cheering on Michael as he continued to make history and rack up gold medals. It represented this interesting moment in time for Phelps where his personal and professional milestones overlapped in an almost cinematic way: The climactic scene of his Olympic journey depicting Phelps swimming off into the sunset, after earning his record 23rd gold medal (and 28th medal overall) in his final race, with 4-month-old Boomer and new wife Nicole by his side.

Fast forward eight months, Phelps can be a dad without an Olympic training schedule, and he's loving it.

"For me, it's the coolest thing in the world," Phelps said in a phone interview. "It's a really exciting process ... and I'm enjoying the hell out of it."

Michael Phelps With Wife And Son

Despite his status as a certified aquatic god, Phelps, like any mere mortal parent would, concedes that raising a child can be challenging at times.

"Swimming was something I did my whole entire life, so it was second nature," Phelps said. "With parenting, Nicole and I have never gone through this. We've never had this experience. But we're both learning through this process together, and I think it's making us become closer."

An educational and unifying force, parenthood has also made Michael mindful of issues potentially affecting his son in the future, as well as those impacting people all over the world. For example, he has recently partnered with Colgate to be part of its #EveryDropCounts initiative, which encourages folks to conserve water while brushing their teeth.

"As a dad, and as somebody who loves water, it was a perfect opportunity for me to speak out about things that I'm passionate about," Phelps said.

Michael Phelps With Boomer In Rio

According to UN Water, water use has been growing at twice the rate of the global population increase during the last century, and 10 percent of people worldwide lack access to clean water. Two staggering statistics to say the least, Phelps is lending his influential voice to share the profound facts and figures, and to explain that just a few small changes to daily routine can make a significant difference. Like say, turning off the faucet while brushing.

"To imagine that over that last 10 years or so we've quadrupled the amount of water usage is just mind-blowing," Phelps said. "I think it's so easy for us to fix, and it's something so small that we can all work on together."

Aside from taking on global issues, Phelps discussed other responsibilities he has assumed as a parent. One in particular isn't so glamorous. Or fun. Phelps is changing dirty diapers -- that's right, Olympic heroes do it too -- and for him, it's grosser than advertised. Even though the diapers he's attending to belong to his own kid.

"I would have never imagined that an 11-month old could produce some of the things that have come out of him ... " Phelps said. "I knew it was gonna smell, but I never thought it was gonna smell that bad… I've [also] been peed on probably twice."

Oh, the joys of parenting. But not everything is as stinky or requiring of a poncho. Phelps gushed about how much Boomer is a fish in his own right, just like his "old" man. In fact, he posted a video on Boomer's Instagram account (which has 782K followers and counting), showing Nicole sitting with Boomer in the water as he splashes around.

"He loves the water and he loves bath time," Phelps said with a laugh. "He loves playing in the pool. So maybe we'll have another swimmer on our hands."

Boomer Phelps

Phelps was quick to note that while it would be cool if Boomer chose to swim one day, whether for recreation or professionally, he wouldn't put pressure on him (just like Phelps' mom Deborah didn't pressure Michael). Phelps said he would support Boomer no matter what path in life he choose to take, but he did also mention that watching Boomer tear up a professional sport would be awesome. Surprisingly, the sport he envisions isn't swimming.

"If he wants to swim, OK, that's great," Michael said. "But if I could choose right now, I would say I'd want to [see Boomer] be on the leaderboard of The Masters heading into Sunday. I think that would be so cool. That would be like a dad's dream-come-true."

Phelps is a self-proclaimed "golf nerd," so his green jacket dreams for Boomer aren't that surprising. And if Phelps (and Kevin Garnett) has taught us anything over the course of his career, it's that anything is possible. Who's to say Boomer isn't the next great American golfer? He's got the genes and athletic pedigree going for him.

If you're wondering how frequently the face of swimming finds himself in the water today, the short answer is on occasion. He made it clear that he isn't swimming as much as he did during his vigorous training days. A few weeks ago, Phelps jumped in the pool and planned on swimming 1,500-2,000 meters. Instead, he went about 500 and called it quits.

"I just said to myself, 'alright, I don't want to do this anymore, I'm getting out," he said. "Nobody's forcing me to do this right now. I'm done. See you later."

Take that, Bob Bowman. (The drill sergeant tendencies of Phelps' old swimming coach have been well documented.)

Michael Phelps, Nicole Johnson, Boomer Phelps

For someone who has viewed swimming as labor for the majority of his life, this is a completely new perspective for Phelps. He can thank retirement, and by extension, Boomer, for providing him with that. Hitting the pool is no longer about gradually -- and a lot of the time, painfully -- building toward a greater goal. It's about having fun.

"The coolest thing for me now is that I can truly enjoy being in the water," Phelps said. "It's just to be able to let go of some of the stress that I have, and I can just relax in the pool. It's a good escape, and I think that's what I love the most about it."

It's amazing to consider that just eight months ago, Michael Phelps won his final gold medal. Since then, he's made the transformation from Olympic hero (which, in reality, he'll always be) to family man. It's a new identity that Phelps has embraced to the fullest, and he's excited to continue on the winding journey that is fatherhood.

"I want to be able to watch the transitions Boomer makes day-by-day, and the little steps he takes to mature," Phelps said. "I just want to appreciate it all."

As for the future, Phelps claimed he does indeed have some "lofty goals." When asked to elaborate, however, Phelps responded in the most Michael Phelps way possible.

"I've never been somebody who's ever shared any goals that I have," he said. "People probably thought I was absolutely crazy wanting to win eight gold medals or wanting to do something that nobody else had done in the sport, but that's just how my mind works. I have all the belief that we can do anything that we put our minds to."

While he remains mum about what the future holds, one thing is likely: Michael Phelps will continue to defy expectations, in parenthood and beyond.

Here are more highlights from our interview with Michael Phelps:

ThePostGame: I have to say, Boomer has one of the cutest Instagram accounts I've seen. Are you impressed with how big a following he's amassed?
MICHAEL PHELPS: It's kind of insane. I posted his first one, and there were like 2,000 people who followed him. By the end of trials, he had like 100,000 followers. And then by the Games, he had almost 800,000. So it was pretty insane to see the numbers absolutely skyrocket over a few weeks. Even in public, people were going crazy screaming his name and saying, "Hi," and waving to him. It's always funny because we're like, "Guys, he's not gonna wave back at you. He's not gonna say 'Hi' back. Sorry. He's a little too young to understand what's going on." But obviously we love the support we get, and we're very, very thankful for it.

TPG: Is there a piece of parenting advice that you and Nicole received going in, before you had Boomer, that you sort of shook off at the time? Or maybe thought was silly, but are now realizing is totally accurate?
PHELPS: The one thing that blew my mind is how somebody said to me, "Never wish that they walk, talk or do this or do that," and I was like, "Why? That's weird. Why wouldn't I ever want my son to talk?" But then you start realizing that time goes by so quickly that by the time you wish for something to happen, they're already walking and talking and you miss that whole step in their life. So I think that's been the one really challenging part for us, is just kind of seeing and waiting and enjoying every single step.

TPG: What is your favorite personal Olympic memory, if you could pick one?
PHELPS: It's too hard to pick one. I've only kind of gotten up to about 2008 so far in terms of realizing what has gone on in my career. So I think for me, it's gonna be a little bit of time before I'm really able to see the one thing that sticks out the most. I mean, I can say probably right now, my most exciting race was my 200 fly from this last time around, but I could also probably say I won a couple races by one-hundredth of a second, four-one-hundredths of a second, eight-one-hundredths of a second, and nine-one-hundredths of a second. There are so many crucial and really important races that I've had throughout my career. It's hard to put my finger down on one.

TPG: Who do you consider the best athletes alive today or even of all time?
PHELPS: It's so hard to say. Every generation is so different. I think one of the coolest things about all sports (and that I've really been fortunate enough to be a part of) is that we see so many of the greatest athletes we have in this day and age. If you look at anywhere from a handful of tennis players to a handful of football players, to hockey players, baseball players, any of the major sports players ... soccer players, you see it.

As a sports junkie and a sports nerd, I'm very fortunate to be able to live in this generation. To be able to see some of the sports history that's been made over the last 20 years is something that is so exciting, especially being apart of it. Even with basketball this year, how many triple-doubles did [Russell] Westbrook have? It's like the unthinkable you see in every sport, so I think that's something that's really neat.

Obviously for me, I was somebody who always looked up to Michael Jordan and what he did in the sport of basketball, and that's what I wanted to do in the sport of swimming. It was always so exciting to watch and see how he handled himself and what he did. It's just an amazing, amazing period for sports in general that we've been fortunate enough to see.

Follow Macklin Stern on Twitter @MackStern24.