Angst does tend to grip New Zealanders at World Cups. The analysis is often neurotic and self-perpetuating in that the more everyone frets, the worse everything seems.
People stop listening, too. Hansen has been asking for patience since the game against Georgia. He's had to remind everyone that World Cups are not won in the pool rounds - that it doesn't matter what happens there beyond qualifying.
He's had to ask for patience - making it clear that the All Blacks have been working towards a plan that would come to fruition in the knockout rounds.
The likes of Georgia and Tonga were useful opponents in terms of working the defence into good shape and honing the linespeed. These were areas the All Blacks felt they were weak at and needed the work.
"Could we feel it building? As I said when I named the team earlier in the week, there's a difference between pool play and a knockout game because if you get it wrong you go home," says Hansen. "If you couple the attitude with the talent, you know you can do certain things.
"When you come to the World Cup you come with a plan and we've had one. It's probably been questioned by a few people, I guess. But the key people who didn't question it were in the group...we had some players who really stood up and played particularly well, but we have just earned the right to go to training on Monday. We can't get too excited."
Keeping everything in perspective is all part of the plan. Just as the All Blacks didn't despair when they were sloppy and unconvincing against Namibia, Georgia and to some extent Tonga, nor are they going to get carried away by winning the quarterfinal.
They took a huge step up in Cardiff but Hansen expects them to lift again this week. That's what has been so smart about this campaign - it gave away nothing in the early stages and in the space of one game, the All Blacks are suddenly looking ominous.
Those who doubted the All Blacks now realise the extent of their potential.
"I think it is a combination of the hard work that we have been putting in here [World Cup] and throughout the year to be honest," said All Black first-five Daniel Carter about the performance.
"A lot of it is about playing what you see and a lot of it is just backing your instincts. When you have done the preparation and hard work leading up to it, it gives you the confidence to go out there and play.
"You are not over thinking which tends to be what we did in previous games. We were trying to stick to a gameplan and trying to remember moves. It wasn't always technically perfect but the fact the desire was there and the willingness that really showed."