The defending Tri Nations champions were ambushed by an impassioned Wallabies unit, who put themselves in position to win the tournament for the first time since 2001 by completely out-enthusing the visitors through the first half.
In the first meeting of the series between the two at Eden Park, the All Blacks leapt from the gates and earned a 17-point halftime lead, but the tables were turned completely at Suncorp Stadium on Saturday night, with the Wallabies blasting out to lead 20-3 at the interval.
McCaw admitted the side had let themselves down with their limp start to the game, but said that the loss had hammered home important lessons ahead of the World Cup.
"We were just beaten to the punch in the first 20 minutes. We struggled to get our game going and they got the momentum and had more intensity than us," he said.
"I think the two games we've had against the Wallabies show there's very little between the teams and it's how you turn up. It's the mental state you turn up in and how you prepare yourself that's the difference.
"When you turn ball over at the tackle, passes don't go to hand, kicks get charged down, tackles get missed - those are really simple parts of the game, but that's what we were (getting it wrong) in the first half.
"I think going forward it's a good lesson that we have to make sure we're on the job from the word go.
"We realise what it's going to take... I guess it's a goodly reminder that winning big Test matches you have to start well."
While the All Blacks showed they were seeking to move on quickly from the disappointing big-Test loss, potentially-serious injuries to forwards Kieran Read and Adam Thomson are likely to cause more concern in the camp.
Read (high ankle strain) left the field early in proceedings, while Thomson (hyper-extended elbow) stayed in the contest and paid the price, failing to hold onto a rampaging Radike Samo in a one-on-one contest and essentially conceding the second try of the match.
Coach Graham Henry said the injuries would be assessed upon return to New Zealand, as would be the contributions of several of his underperforming starters.
"Some guys would have been disappointed with how they played - they didn't play as well as they normally play or as well as they played to get into the side," he said.
"That's the challenge; there are 30 guys in the team and they're all competing for positions and hopefully that'll continue right through the tournament.
"There'll be some people that will be disappointed that they didn't take advantage of the opportunity."
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