"It doesn't take that much ... if something is off, confidence is down ... for things to turn around really quickly."
Despite this, however, McCaw doesn't think there is any reason why the All Blacks won't keep winning everything.
"There's not, really. People say at some point it has to come to an end but that's just a perception I think," McCaw said.
"As long as you keep each week readying yourself to put the performance out there, you can keep going."
What will interest Aussie fans most about Chasing Great, is the role rare Wallabies success played in securing both the 2011 and 2015 World Cup.
After Australia's win over the All Blacks in Sydney in August last year, McCaw speaks about how he deliberately stayed on the field "to take the medicine ... and help sharpen the axe for next week".
"I hate losing. I hate it even more losing to the Wallabies," an agitated McCaw says.
Australia used the victory to give themselves belief they could win the World Cup but the Kiwis used it to remind themselves they could lose another.
McCaw admitted it was a timely defeat for the All Blacks, at the safe distance of a few weeks before the World Cup and not inside it.
"What it did, it firmly planted us back with feet on the ground. If anybody was getting a bit carried away or subconsciously thinking we had it all under control, it shook us and brought proper reality back," McCaw said.
"I know going into the World Cup final, having that memory of only a few weeks earlier, we spoke about if we don't get it right, we could come second here. There is a lot of respect between New Zealand and Australia.
"I remember in 2011 it was similar too, we lost a week before the tournament in Brisbane. Going into the semi-final (against the Wallabies) of that World Cup, that defeat wasn't too far out of the mind either. We had to get it right or we would be finishing up."
