He told World Rugby that was his belief when putting aside his allegiance for the All Blacks to do well.
"You are not too sure what might happen. From a New Zealand point of view, in the past you sort of always knew that if they can put it together they can go and get the job done, whereas after the last year you sort of go, 'jeepers, there is going to have to be some improvements to put the team in the right spot'."
McCaw said the form of Ireland and France have been setting the pace and were the favourites in the minds of northern hemisphere fans.
He believed Ireland had a chance to break their quarterfinal hurdle at World Cups.
"As we found out in years gone by, where you are ranked going into a World Cup doesn't necessarily count for a whole lot.
"I got to see the Irish in New Zealand last year for three Tests, and there is quite a strong resolve about them, of knowing they are on a mission.
"The way they put together that series win was pretty impressive, and they have backed it up again recently, so it is going to make it interesting."
Given his experience being tipped out in the 2007 quarterfinals, McCaw said teams could not start getting ahead of themselves, which contributed to the All Blacks' disappointment.
"Although we had a team good enough to win, and we had a game plan and strategy and all of that, what we got wrong was we didn't address what happens if things go wrong – injuries [referee] calls, et cetera.
"You can have all the best intentions when you go out on the pitch, but what do you do if it doesn't go quite right?"
The lessons from that experience were used to hold out a savage French assault in the 2011 final.
"I think you can get scared and hope you are just going to play well and think that it's not going to come down to the bounce of a ball, or one or two skills. But, actually, that is why it is special to win. You have got to deal with those [unpredictable] moments, and that's what we did."
After that success, McCaw got to experience another four years of an All Blacks team playing exceptional rugby and was able to play out his career at a fourth World Cup and as a second-time-winning captain.
"You knew finishing at a World Cup would either be extremely happy or disappointing, no middle ground. It was a great way to sign off.
"The final had a bit of everything. For the first half, we played outstanding rugby and, again, like early on in the 2011 final against France, the scoreboard didn't reflect how on top we were. But we scored early in the second half, and I felt this could go our way.
"All credit to the Aussies, they hung in there, and we had a yellow card, and all of a sudden, it was back to, 'this could go either way'.
"Towards the end, once we got the game under control again, rather than just praying for it to finish like in 2011, I was enjoying the moment because it was fun, and it had quite a different feel to four years earlier.
"I remember thinking at the end of that 2015 tournament, 'why would you ever want this to stop?'"
But he realised nothing would ever be the same as others were moving on while many of the requirements to play for the All Blacks at a World Cup were getting hard.
He explained that what he missed from the game was pulling on the jersey before the game, hearing the crowd when running out to play and then the feeling when sitting in the dressing afterwards.
"But as soon as that first whistle goes, and you see the first big tackle, you go, 'ohh, I am quite happy where I am these days.'"
McCaw expects some surprises from the 2023 World Cup, especially during the pool play.
"When you look at the top 10 in the rankings, results have shown that the teams ranked seven, eight and nine have gone the ability to knock over one of the big guys once. But to go on and win it, you need to do that three weeks in a row, and I am not sure some of those teams have got the ability to do that.
"The good thing is those teams could get into a quarterfinal and cause some real carnage. And if you get a couple of results like that, it might open the door for someone else to have a bit of a run and get more belief that they can do it.
"That's what's made the lead-up to this tournament so interesting."