Namibia had taken the game to the All Blacks, getting to 10-9 down late in the first half before the All Blacks started to take control.
"I don't think it's a major issue, I just think it's something that happens in sport," he said.
"It's a good reminder to all of us that every time you play you have to get yourself in the right head space to get yourself to the level that you want to perform at," he said.
Looking at the reason for not having the right attitude, Hansen said with a four-day turnaround there was only time for two soft training runs from a physical point of view and that made it easier to turn up 'not quite mentally right'.
"And that's one of the biggest challenges in sport, particularly when you know you are going to play an opposition that, and again I'm not being disrespectful here, you know you should beat.
"So players and coaches and management can get a little bit lost in their mental preparation, for the want of a better word, and when the opposition which happens every time we play somebody are right up for the game then we can look ugly and messy and that's what happened in the first half.
"We were a little bit off the pace, our breakdown work was poor, there was no urgency to get the job done," he said.
The side were not helped by yellow cards against them for high tackles on players falling at the time of impact – props Nepo Laulala in the first half and Ofa Tuungafasi in the second.
Hansen said he thought the two yellow cards were fair under the guidelines being applied but it was tough, especially when a player was falling and a tackler was committed. There would be times when connection was made and he wasn't sure how it could be avoided.
"If you don't use your arms then you are going to get done for a no-arms tackle so it's difficult and I think that's why they've allowed the mitigating circumstances and it only becomes a yellow card.
"It is difficult at the moment and the powers that be are asking us to tidy it up and each team is doing their best but there will be circumstances that are just about unavoidable and unfortunately that is just where our game is at the moment," he said.
Hansen said there had been a lot of entertainment in the game, some great tries scored and Namibia had contributed with some 'great stuff' as well.
The second half had been the more enjoyable.
"The first half we didn't turn up with the right attitude and allowed Namibia to partake a lot more than they should have and that's not being disrespectful to Namibia but we sorted that out at halftime and came out with a bit more direction and understanding what we wanted to do and played pretty well.
"I thought Jordie Barrett coming in at first-five played outstandingly well and how could you not mention the try at the end, it was a special one. It even got me out of my seat – not too many things do that," he said.
Barrett was elated with getting another 80 minutes in the All Blacks' jersey.
"The more minutes young players like he can have in the jersey they lap it up. I think he's pretty excited, and happy too, with how he played. He did the job that both Ian [Foster] and I wanted him to do and the team needed him to do. He drove the team around the park. Once we started to deliver some go-forward ball he was very, very good," he said.
It was clear it wasn't his No.1 position but to come out and play like he did he should be proud, Hansen said.