The most decorated Olympian in history, Michael Phelps is by any measure a great success. A legend, even. But he has not always been happy.
Phelps' first trip to the Olympics was in Sydney, when he was just 15 years old. He didn't win any medals, but it was clear from his first appearance that the tall, skinny kid with long limbs had tremendous potential in the pool.
In Athens in 2004, Phelps took home six gold medals and two bronze. In Beijing in 2008, Phelps won gold eight times. And in London in 2012, Phelps won four gold and two silver medals.
But Phelps' rise to the top of his sport was not without stumbles. Phelps was arrested for a DUI when he was only 19, and in 2009, Phelps was criticized after a photo came out of him smoking a bong.
In 2014, Phelps was again arrested for drunk driving. The champion of three Olympic games who had accumulated 22 medals fell into a deep depression.
At times, he even felt suicidal.
"I've seen the darkest of the dark. And there are days where I didn't want to be here," Phelps, now 31, tells CNBC.
These days, though Phelps is better, he still struggles, and he's frank about that.
"I'm not perfect. Nobody is. I will be the first one to admit a mistake when it's made. That's the only way you are able to move on and learn from that mistake," says the swimmer. "By no means has my life been absolutely perfect."
Phelps has turned a corner, though. He feels more stable now than he was a couple of years ago. Nine out of 10 mornings, he says he wakes up happy. Before his time in the treatment center, Phelps says there were periods of his life where he would wake up in a bad mood six out of 10 days.
"Being able to come out of the other side and just to work and learn things about me that I never knew, I didn't want to know at that point — you know, I think it changed my life," he says.
In Rio last year, Phelps added six medals to his stack, bringing his tally of Olympic medals to 28, and making him the most decorated Olympian in history. Phelps is a husband and new father, and he is launching his business career, which he aims to model after Michael Jordan's.
For example, Phelps spoke to CNBC from the New York City showroom of direct-to-consumer mattress brand Leesa, with which he has recently entered into a four-year brand partnership.
Going forward, Phelps hopes his personal struggles, as well as his athletic successes, can be an inspiration to others.
"I look back at things that I've been able to accomplish and everything that I have, and I'm just so happy with where I am in life," says Phelps.