The eager young flanker had been going berserk at Canterbury trainings in the early 2000s, repeatedly ducking into rucks to steal the ball and, subsequently, annoying senior squad members.

Enough was enough, the old heads agreed. Something needed to be done.

So established forwards Todd Blackadder, Reuben Thorne, Scott Robertson and Angus Gardiner marched up to coach Hansen and demanded he tell McCaw to curb his enthusiasm or they might have to give the cheeky pup a slap.

"Toddy, Reuben, Razor and Angus Gardiner came to me at one point and said 'look if he comes into another ruck and pinches another ball we are going to snot him'," Hansen recalled ahead of McCaw's game against Wales.

"I said 'if you snot him I will be snotting the lot of you, so leave him alone. He's only a baby, just look after him and get there quicker than he is'."

Even back then, Hansen said, McCaw wanted to be the best.

But the coach was also careful to ensure the enthusiastic No 7 didn't unwittingly make enemies.

"I had to go to him quietly and say 'let them win a couple, you are starting to piss them off'," he said.

McCaw, 33, is the current immortal of New Zealand rugby and Hansen wants to ensure his milestone of leading the All Blacks in 100 tests gets the recognition it deserved.

It was Hansen, then working as Canterbury's academy manager, who saw something special in McCaw as a teenager.

The 18-year-old was playing for Otago Boys' High School against Rotorua Boys' in a national secondary schools play-off match at Lancaster Park, setting a firecracker off inside Hansen's head.

Hansen marched to Steve Tew, then the Canterbury chief executive and now NZ Rugby's chief executive, and jabbed a finger at him.

"I went into Tewie's office and said [no matter] how much he costs, just get him. This kid's special."

Tew shook his head, reminding him that Canterbury and Otago had a gentleman's agreement not to poach each other's players. But Otago made a dreadful mistake. They broke that deal and, suddenly, all bets were off.

"They pinched Sam Harding from Christ's College, so we got him [McCaw] up to Lincoln College," Hansen said.

"There was just something about him from day one."

McCaw joined the academy, was given some extra cash to make him feel appreciated, selected for Canterbury and the Crusaders and in late 2001 debuted for the All Blacks against Ireland.

The first time McCaw led his country was almost 10 years ago to the day - also against Wales at the Millennium Stadium. The All Blacks squeezed home 26-25.

When Tana Umaga retired after the 2005 season, the path was open for McCaw to take the captaincy and there has never been any question of him relinquishing the role - except, of course, after the capitulation to France in the 2007 World Cup quarterfinal in Cardiff.

That really stung McCaw, forcing himself to ask whether he wanted to continue as skipper.

"There was perhaps a point after the 2007 World Cup where I questioned I was good enough to do it, or the right person to do it, which I suppose is natural after a disappointment like that," McCaw said.

It was, he said, a fleeting moment of self-doubt. He then realised that being a leader stoked his enthusiasm: "You have to want the responsibility, want to put yourself under the pressure that comes with it."

It was during the redemption tournament of 2011, when McCaw played with a broken bone in his right foot, that Hansen's admiration for "Ricko" spiked to new levels.

"To do what he did with his foot broken just showed the courage of the man," Hansen said.

"The mental strength he had to play as well as he did and to be there, to keep the team confident.

"His ability to stay in the fight and get all the way through the tournament was massive. Even after the final - he walked with me to the media conference afterwards and he was exhausted.

"It was over, the relief was immense among all of us but I think, for himself, particularly because he felt a lot of responsibility for '07. Which wasn't because it just wasn't him who lost it, we all lost it."

McCaw isn't perfect. He still concedes the penalties for lingering too long at the back of a ruck or for poor timing when lunging for a turnover, and there has been the odd yellow card along the way.

Hansen says his captain has had to learn to be more flexible in his thinking and McCaw admits he is now more open to listening to other senior team-mates.

And he has also learned to never concede.

"One thing I know with rugby, and I always think, is that even when you are under the pump - no matter what - at some point it will change," McCaw said.

"You have to make it change but it will come back your way and you have to be good enough to take those opportunities."