While he played nearly three-quarters of the earlier Test against Australia in the position, it was a full-fledged effort on Saturday. He remarked that he wouldn't have to wake up in the morning to feel the effects of the different, and more physically challenging, role at second five-eighths.
He was already feeling the effects.
"It's different. I felt like I couldn't get out of fourth gear, particularly with accelerations, decelerations, and more collisions.
"That's just the nature of being in the midfield. I still love playing 15 [fullback], and I love playing 12 [second five-eighths]. I just enjoy an opportunity to play for the All Blacks."
Barrett was able to give something back by causing his markers to feel his strength with some charging runs at their line.
"Rugby hasn't changed, and if you can get some gain-line off set-piece and nullify it on the other side of the ball, you go a long way toward winning a match.
"They've got some outstanding carriers, Valentini, Pete Samu and some good outside backs and midfield players with some feet."
He said he prepared for the traffic that came to his area and concentrated on that in his preparation.
"They have some big ball carriers particularly off set-piece and if they can get some ascendancy and gain-line it bleeds out into the rest of their game so I knew that if we knocked it on the head there that we could bring their game to a bit of a halt so it was a big mover there tonight."
"If we could stop them at the gain-line it helps the rest of our boys. Our forwards one to eight were outstanding tonight and it makes the backs jobs a lot easier."
The All Blacks' Championship-winning effort was driven by a desire to show their worth to home fans and the closeness of their first Test with Australia.
"We weren't too proud of our last quarter last week, and it could have gone in a different direction, so we knew, coming back to New Zealand, and Eden Park, it's a place where we hold a high account, and we wanted to put on a performance that our fans and New Zealand are proud of.
"Consistency is important, it's what we strive for every day as All Blacks. The last few months haven't been up to standard but I think we're heading in the right direction now."
The scrum and maul had allowed the All Blacks to piggyback their way up the field and then kick to gain 50 metres went a long way toward winning Test matches.
Barrett said his employing the spiral punt was something he had been working on, especially with the Adidas balls used in New Zealand. David Hill and Ian Foster had been encouraging him to use the kick, and he had been practising it a lot.
"If I have got time on the ball I feel like I can peel off an extra 10-15 metres so I was lucky to get a couple away."