"I had no idea what I was doing back then. When I started, I felt like I needed to have all the answers, to know it all myself, always be the guy talking. But as time goes on you become more comfortable if someone else has the answer and you go with that. You get satisfaction seeing other guys make the right calls."
He added: "At the time I'd only had half a dozen games as captain of Canterbury and I thought 'that's enough, it can't be that much harder', but you look back on the lessons you've been through, the ups and downs, and ... you wonder how you survived."
He said he found it hard to put into words what reaching the milestone would mean to him, adding it was a privilege to be in the position he holds.
McCaw was more comfortable talking about the lessons, including his doubts after that infamous defeat to France. He questioned whether he was the right man for the job, but once he decided he was, he used the experience to fuel the fire for the 2011 victory at Eden Park, a test against a World Cup nemesis which coach Steve Hansen said left McCaw, playing with a broken foot, "exhausted".
Hansen first saw McCaw when the openside flanker was playing for Otago Boys High School against Rotorua Boys at Lancaster Park in his position as Canterbury Rugby's academy manager.
He was in no doubt as to the quality of the then youngster, telling Steve Tew, now New Zealand Rugby's chief executive, but then the boss of Canterbury Rugby, to sign him immediately.
"There was something about him from day one where he had the courage to go into the dark places," Hansen said. "He was a great thief over the ball and he had the ability to keep bouncing up no matter what happened.
"He's a shy man, he probably doesn't come across like that now, but he's very shy and he very much keeps things to himself. You have to prise it out of him a wee bit."
McCaw, who said his parents Don and Margaret are travelling from Canterbury to Wales for his milestone, reached in his 137th test, said his role model as captain was Todd Blackadder, the former All Black skipper, for his willingness to lead from the front.
For Hansen, McCaw's ability to do that and more takes him to another level.
"What stuck out the most for me was the World Cup in 2011 - not just the final - but to do what he did with his foot broken just showed the courage of the man and the mental strength he had to play as well as he did to be there and keep the team [together].
"We'd already lost Dan Carter [to injury] ... his ability to stay in the fight and get all the way through to the end of that tournament was massive."
Most tests as captain
100 - Richie McCaw, All Blacks, 137 tests in total from Sunday.
84 - Brian O'Driscoll, Ireland and British and Irish Lions, 141 tests in total.
83 - John Smit, South Africa, 111 tests in total.
