All Blacks coaching legend Sir Graham Henry thought he was at the top of his game, when he was asked to guide the 2001 British & Irish Lions tour to Australia.
After four years coaching Wales, he was known as 'The Great Redeemer', leading them to 10 consecutive test victories, including their first over South Africa. Henry was the world's highest-paid rugby coach, earning a reported 250,000 pounds (NZ$486,000) a year.
So he wasn't prepared for the emotional crash, after returning from the Lions' test-series loss to Australia.
Sir Graham has revealed his mental health issues on Three's Match Fit series, which has assembled a squad of former All Blacks, most now retired 10-20 years, to confront life challenges of middle age.
While Henry and former NZ captain Wayne 'Buck' Shelford are charged with guiding the former superstars towards one last competitive outing, they already have first-hand experience of the pitfalls that await high-performance athletes during - and after - their careers.
"The biggest worry for professional coaches these days is the mental wellbeing of their players," says Henry. "We know about strength and conditioning training, but we don't know a lot about mental fitness.
"I've been very lucky to have a fantastic wife who was hugely supportive. I had some mental wellbeing problems when I was coaching - I had depression.
"I was coaching the Welsh national team and they asked me to coach the Lions, which was a real honour. I should have said, 'no, I'm too busy', but I thought I was bulletproof.
"After the Lions tour I hit the wall."
After winning the first test, the Lions lost the last two against the Wallabies - the first time Australia had beaten the tourists in a series. The tour was marred by division between test and midweek squads, with some ex-players pointing at poor management and a lack of team spirit.
The pressure of being the Lions' first non-United Kingdom coach took its toll on Sir Graham.
"I didn't know I had depression, but I just didn't want to do the job any more."
Wife Raewyn, who had coached the Wales national netball team, was in Singapore when she received a phone call from friends, warning her of Henry's condition.
"That was difficult, but I could see it coming," she says. "He puts a lot of pressure on himself."
Henry resigned as Wales coach and withdrew to Christchurch, where ran through the Akaroa forests every day for two weeks.
"There's a massive connection between the physical and the mental, so the combination of exercise and good mates and people you could talk to and getting away from the pressures of the job were extremely important," he recalls.
"I learnt so much about myself and how to handle that depression."
That insight served him well five years later, when Henry's All Blacks were upset by France in the Rugby World Cup quarter-finals. Despite public outcry, he was reappointed to the job for another four years, culminating in the 2011 World Cup triumph.
"Because I had gone through the depression after the Lions series, I had the tools to handle it, otherwise I would have finished coaching then."
Match Fit was made with 'NZ On Air' funding, and runs over October/November, 7:30pm Tuesdays, or on Three Now.