The Wollongong athlete took to social media on Thursday to announce his retirement from the sport

With the postponed Tokyo 2021 just six months ago, McKeon's decision may have caught some people by surprise. However, the two-time Olympian says the timing is perfect.

"It's a decision that I've been thinking about for a little while. It's come to me through talking to other people and everything," the 28-year-old said.

"But I always come back to the point that I'm proud of what I've achieved in the sport. I've achieved a lot and I probably wasn't supposed to get this far in the first place, to be honest. And I don't think going into a third Olympic Games will make me more proud of myself."

Read more: 'Illawarra' the final piece of the jigsaw

So, did COVID-19 prove influential in his decision. McKeon says it's a combination of "yes" and "no".

"That's just life, there's hurdles everywhere you look. I've had multiple issues with my shoulders, I'm probably going to have to have another shoulder surgery, and that's played a little bit of a part in it," he said.

"But I'm ending it on my terms, not on the terms that I missed the team or anything. I'm ready to step on to the next part of my life. I'm proud of what I've done, I've had quite a journey."

Read more: 'Wollongong' Phoenix captain eyes off opening A-League victory

McKeon's journey to the top began from humble beginnings when, like many Australian kids, he learned to swim at a tender age.

He stepped away from the sport when he was 10, but that break wouldn't last and his rise through the ranks would prove rapid.

"I wanted to win the school carnival at my school, Illawarra Grammar School in Wollongong, when I was in grade 12," he said.

"I won that school carnival in 2010 and I was lucky to go to the Olympics 18 months later. So I guess I had a steep incline to go to the Olympics and I'm proud of that."

McKeon competed in the 400-metres freestyle in London 2012, finishing fifth in his heat. However, he failed to qualify for the final. He also helped Australia finish fifth in the 4 x 200m freestyle relay.

Two years later, McKeon made a big splash at the Commonwealth Games in Glasgow. He teamed up with Cameron McEvoy, Ned McKendry and Thomas Fraser-Holmes to win the 4 x 200m freestyle relay and also claimed silver in the 400m freestyle.

In 2016, McKeon qualified for the Rio de Janiero Olympics. This time he was joined by his younger sister Emma. He finished seventh in the 400m freestyle and was part of the Australian 800m freestyle relay team that finished fourth.

McKeon then impressed on home soil at the 2018 Commonwealth Games on the Gold Coast, claiming a gold medal in the 4 x 200m freestyle relay.

So what does he look back at most fondly?

"You certainly go past the Olympics. And to go to two Olympic Games was pretty special," McKeon said.

"Being in the Olympic finals, getting a Commonwealth Games gold medal, standing up on the podium and singing the national anthem were all pretty cool. It's something that I'll be telling stories about for the rest of my life.

"But I'm very much about the journey of swimming and what it's taught me, and it's grown me into the person I am today. And I will never forget that. Swimming is a sport that teaches people a lot more than they realise and they probably don't realise until they're older. And I've learned a lot from swimming that I'll be able to take into the rest of my life."

Out of the pool, McKeon is most proud of the relationships he formed with his Australian teammates.

"I've always been good friends with everyone on the team. Early in my career, some of the boys around my age like Ned McKendry, Thomas Fraser-Holmes became my friends," he said.

"And then, a bit later on, I became good friends and rivals with Mack Horton. He's been a great friend of mine, we've roomed together, we've trained together. They're friendships that last a lifetime. My parents have both been to the Olympics and Commonwealth Games, and some of their closest friends went to the Olympics and represented Australia too. And I'm now friends with their kids. One of my best friends ... his dad went to the Olympics and roomed with my father. So it's definitely a family sport."

Read more: Balgownie aiming to resume Cricket Illawarra campaign on the right foot

And, of course, when it comes to family, younger sister Emma has played a big role in McKeon's journey.

"It was pretty awesome to go to the Olympics with 'Em', to go to the Commonwealth Games with her. In 2014, when we won quite a few medals together, that was awesome," he said.

"We've always been there for each other, she was one of the reasons that I started swimming. Back in 2010, when I wanted to win that school carnival, I also wanted to beat my 15-year-old sister. And then Emma stopped swimming in 2012 and she came to the Olympics to watch me, and then she came back to in 2013. So I'd like to think that I inspired her to come back.

"I'm proud of what I've done, I've had quite a journey and to be able to do it alongside my sister was pretty special."

McKeon, who lives with Emma on the Gold Coast, is now keen to focus on the next chapter in his life. He plans to return to Wollongong one day to be closer to his family and friends, while he is also keen to look at swimming coach options.

However, for now, he is just enjoying the chance to stop and relax.

"I definitely won't miss the 5am starts," McKeon said.

"Actually, this morning, I woke up pretty early just naturally. I got up and went and floated in the ocean for a while. I was thinking to myself that I'm pretty free now, this is the most free I've felt in my life. I started this sport when I was at school. When you're at school, you're in a routine each and every day. And I did this for the last 10 years with a routine that's even more intense than school, more intense than most things are really.

"So it's a weird feeling that will take a bit of time to sink in, but I'm excited to just enjoy myself a little bit, sleep in and go for little swims."