South Africa's humbling by Japan has taken a physical toll on Heyneke Meyer, but he consoles himself in the knowledge that the biggest upset in rugby history has galvanised the Springboks' World Cup quest.
Since their stunning defeat by Japan in Brighton three weeks ago, the 1995 and 2007 champions have reeled off convincing victories over Samoa, Scotland and the United States to set up a quarter-final against Wales.
Meyer went through some dark moments as he faced up to the challenge of rebuilding South Africa in the wake of their humiliation at the hands of the Brave Blossoms.
And while the head coach insists knockout rugby begins all over again when the Springboks launch the quarter-finals at Twickenham on Saturday, he now knows the true character of himself, his tracksuit lieutenants and his players.
"I cried for about 24 hours after losing to Japan. Then I thought about committing suicide for an hour - I'm joking. As you can see, I've got much more grey hair," Meyer said.
"It's not easy when you come to the World Cup and after the first game you have to win every single match, but I think it helped us.
"Losing to Japan was a very tough day, but we had to learn from it. There have not been leaders in times of peace, it's when there is war that leadership and character come through.
"When things go well and you have a brilliant side, that's when the job of coach is easy.
"But when you are under pressure, people write you off and players start to doubt, you fall back on your past experiences. You show resilience and character.
"We knew we had to win all three games after Japan to progress. We took it on the chin. The most important thing about bouncing back was not to make any excuses.
"Looking around you, you know the management team and these are guys who you can trust going into battle.
"But I have said to the players this week we are right back to where we started and we have to go through it all over again.
"We like to have people writing us off and putting pressure on us because it enables us to show who we are."
South Africa have made one change following their 64-0 victory over the USA, recalling JP Pietersen after the wing recovered from a knee injury.
The bench has been strengthened by the return of seasoned quartet Adriaan Strauss, Jannie du Plessis, Ruan Pienaar and Pat Lambie, but Victor Matfield has been ruled out by a hamstring problem.
While South Africa's starting XV contains 686 caps with a further 337 caps on the bench, lock Lood de Jager and centres Damian de Allende and Jesse Kriel are international rookies. Fly-half Handre Pollard is only 21-years-old and has 17 caps.
"I am a big believer in you have to have experience in the midfield, but youngsters all over the world have shown what they lose in experience they make up for in fire and heart," Meyer said.
"Sometimes the big occasion doesn't count. I always say to the youngsters that Boris Becker was the best at 17 when he won Wimbledon. Mike Tyson was a machine at 21 and I can keep on going.
"Look at the best generals like Alexander the Great, who was 21. So it's a mindset. What the youngsters lack in experience they will definitely make up for in heart.
"Some young guys are very strong individuals and know exactly what they want out of life."