While the All Blacks were not as heavy on experience as the 2015 side, many of the same management team were involved again and that was important for the playing side, Barrett said.
Having such an experienced management team created a lot of confidence in what they were trying to do and what they were teaching the players.
"As players we're in the best hands possible and we have every opportunity to be the best players we can be under them," he said.
While the players were out on the field attempting to achieve the desired game plan, a lot went into the preparation each week around structures and the plan but also around the mindset and mental aspect which was Gilbert Enoka's area of speciality.
"We're in great hands with our coaching group and I feel privileged as a player to be in that position," he said.
A successful World Cup campaign would see the All Blacks away for nine weeks and Barrett said to cope with that he broke each week down and had time slots to do what was best for him in chilling out and refreshing mentally. That could mean going out and embrace the culture in Japan. It was something he did wherever the side travelled.
"Making sure you get that balance is crucial in tournaments where those who get to the finals will be there for a long time," he said.
Barrett said a lot had changed since he first came into the side in 2012 and even since attending his first World Cup in 2015. He was older, married, more demanding which came with having more responsibility, but there was no other place he would rather be.
"I'm really excited about what's coming so it's going to be a big challenge," he said.
The Japan experience was different, as every tournament was. He said in 2015 it had been Dan Carter's last tournament and last hurrah in the black jersey and while Barrett hoped it wouldn't be his last tournament it didn't mean he wouldn't have the same expectations that Carter would.
"There's no doubt that we're going there to win it and play the best footy we can so personally my expectations don't change whether it's a normal Test match or a World Cup tournament.
"I'm going out there to try and be the best player I can be," he said.
There was an excitement about having come through the weekend's Tonga game without injuries among the squad and there was a desire in the group to get on the plane and ready to prepare.
"It was great to play an expansive game and have so much ball where we could dictate terms. It was perfect in that sense, having a hit-out, being able to play through some structures and everyone got a good run and, most importantly, we didn't pick up any injuries, so we're all fighting fit and looking to get to Japan," he said.
Barrett said the side's intent had been good, especially in keeping the foot down during the first half and being relentless in the way they played and that was one of the positives he took from the game.
Watching fellow Hurricane, loose forward Ardie Savea, Barrett said his work rate was immense.
"The influence he has on a rugby game when it comes to the breakdown, then you see him run around wingers on the edges, he's probably our most influential player in terms of work rate that we have at the moment," he said.
Barrett said it wasn't something that just happened as a result of the extra starting time he got in the wake of flanker Sam Cane's neck injury last year.
"We've known for years how good he is and I've been fortunate enough to see that as a teammate for the 'Canes so, look, it's great that he's starting and we've been able to see him for the full 80 minutes and not 30 minutes off the bench here and there so if that's the combination going forward then that's great for us," he said.
Barrett said captain and No.8 Kieran Read's attitude was selfless when moving to the blindside of the scrum to allow Savea to pack at No.8.
"He understands that's the best thing for the team when you've got an explosive ball carrier like Ardie, why wouldn't you? Not to say that Reado can't do a good job off the back of the scrum but Ardie's pace – we saw how quick he is at the weekend," Barrett said.