Fifty years ago, Elaine Tanner brought home three Olympic medals from Mexico City, more than any Canadian had ever won. The country's athletes had earned only two other medals in those 1968 Games.

It should have been a shining moment for the accomplished teenage swimmer, but instead it marked the beginning of a two-decade struggle with depression and anorexia that eventually landed her homeless, on the streets of Vancouver.

The catastrophe for Tanner, who had been the favourite going into the Olympic Games, was that her medals were all the wrong colour — two silvers and a bronze, but no gold.

"I hadn't even dried off and the press was saying to me, 'Why did you lose? What happened?'" she told CBC News in an interview this week.

"It was devastating. I was only 17, I wasn't mentally prepared."

Elaine Tanner poses during a visit to Kelowna in 2010. (Supplied by Elaine Tanner)

A half century after what seemed like an insurmountable disappointment, Tanner is now happy and healthy, and brimming with advice for the athletes who've competed in this year's Winter Olympics in South Korea.

Her wisdom could be particularly poignant for members of the Canadian women's hockey team, who missed out on gold for the first time in 20 years, and the men's and women's curling teams, who were shut out of the podium altogether.

There's no point in denying feelings of sadness or disappointment, but Tanner believes keeping things in perspective is crucial.

"Our lives are basically a book, and we write that book. When you look back, as you turn the pages of your book, that sport is really just a chapter or two," she said.

"As an individual, you are far more than that. You have more depth — you have layers of who you are. You're not just one thing."

Marion Lay, Angela Coughlan, Elaine Tanner and Marilyn Corson display their bronze medals at the 1968 Olympic Games in Mexico City. (CP PICTURE ARCHIVE/STF)

This wisdom isn't the result of a sudden epiphany. It took decades of hard, emotional work and soul searching, Tanner said.

When she travelled to Mexico City as a 17-year-old, she didn't have the support of a sports psychologist or the mentorship of more experienced high-level athletes.

When it came to the emotional pressure of the Olympics, the tiny phenom nicknamed "Mighty Mouse" was basically on her own.

And the expectations were huge. Tanner had won seven medals at the 1966 Commonwealth Games, another five at the 1967 Pan Am Games, and been awarded the 1966 Lou Marsh Trophy, given to Canada's top athlete.

Elaine Tanner, Canada's swimming sensation, wins a gold medal in the 100-metre backstroke. 7:44

"Instead of being a dream that I had as a little girl to win Olympic gold … all of a sudden my dream was shared by an entire nation," she recalled.

"My psychology turned and I thought, 'Oh my gosh, what if I don't win, what if I let the whole entire country down?'"

By any reasonable measure, she did her country proud. No Canadian woman had won an Olympic medal in swimming before, and she won three, in 100 metre and 200 metre backstroke, and the 4x100 metre freestyle relay.

Nevertheless, the newspaper headlines back home declared "Tanner loses gold."

Then-prime minister Pierre Trudeau meets with Elaine Tanner at the 1967 Pan Am Games. (Supplied by Elaine Tanner)

Tanner was crushed. Track and field legend Harry Jerome — a fellow British Columbian — noticed her dejection, and whisked her away from the media glare in the Olympic Village, grabbing an official's car without permission and treating her to her first alcoholic drink at a nearby cantina.

But that was just a temporary reprieve from her sorrow. Her self esteem was destroyed, and there was no system in place to support her when she returned home to Vancouver.

Over the next 20 years, she struggled to find a steady job, went through two divorces, gave up custody of her two children, developed a life-threatening eating disorder and finally ended up living out of her car in Vancouver.

But in 1988, things started to turn around when she met a lifeguard named John Watt. He'd had a hard life, too, losing a brother to suicide, and his home and marriage during the recession of the 1980s.

They fell in love and began the long process of putting their lives back together.

Now married for more than 25 years, they split their time between B.C. and Ontario.

Elaine Tanner displays the seven medals she won at the 1966 Commonwealth Games. (Supplied by Elaine Tanner)

Tanner turned 67 on Thursday. She's still very active, working out for three hours in a session, according to her husband.

She often turns to writing to work out the twists and turns of her life story. In 2015, she published her first children's book, Monkey Guy and the Cosmic Fairy, a tale she'd originally written to entertain her three young grandchildren.

Keeping a sense of childlike wonder has been one of the keys to her happiness, she said, and she advises everyone to do the same.

"Live your life fearlessly, don't be afraid to venture out, keep your sense of wonder, keep an open mind," Tanner said.