Luke Ronchi remembers vividly the first time he realised Kane Williamson was truly special. The former Australia and New Zealand wicketkeeper-batter, now batting coach of the country of his birth, had played with a generation of Australian greats, including Ricky Ponting, Michael Clarke, Michael Hussey, Justin Langer, Damien Martyn and Simon Katich.
But he had heard nothing like what he did from Williamson after his 140 at the Gabba in 2015 against Mitchell Starc, Mitchell Johnson, Josh Hazlewood and Nathan Lyon.
"He was talking about the technique he was starting with in his innings, and what it was," Ronchi told ESPNcricinfo. "He said he had worked out how they were trying to get him out by bowling across him and trying to get him to nick off. He said, 'I had to change my grip on the bat and my bat swing, [and] the motion I was making. I just had to make it a little bit different and do it this way'.
"I was like, 'Mate, that's just freaky. How do you have the ability to go and change technique mid-innings?' And he was just like, 'That's what I needed to do'. He was just so calm and clear about it. A lot of guys have their technique, and it is what it is. But sometimes, conditions, bowlers and whatever it is - they just can't change what's in front of them. When you can see the greats of the game just adapting on the fly, I think that's what sets those greats apart from other great players."
Williamson is preparing to bring up yet another century at the Hagley Oval. This one will be his 100th Test.
He is preparing in the same way he has for his previous 99 - methodically and calmly. He's still striving for perfection after all these years of near-perfect batting. Although he now knows after 99 Tests of trying that perfection is impossible, so he is simply trying to be better than he was the day before.
"When you're younger, you're looking for something that's perfect," Williamson said two days out from the milestone match. "And after trying really hard to define something, you realise that you've probably searched in all corners and it doesn't really exist.
"As a player, it's trying to get some clarity on your strengths and your weaknesses, and while putting time and effort into improving those, also accepting that things won't be perfect and it's about how can we be effective. I think trying to help the team move forward is a really motivating factor for me. The art of batting, I'm still learning. Every day you have different conditions; you have different opposition."
Williamson has every right to rest on his laurels. Coming into the series against Australia, he had scored seven Test centuries in 13 innings - including three in four against South Africa. But Williamson is still searching to get better, as Ronchi highlighted how Williamson has adapted to the different pitches during New Zealand's home season this year.
"We played at Hamilton against South Africa, and the wicket was playing a certain way, and then we come to the Basin Reserve against Australia on a wicket that's bouncing back of a length, [and] it's turning from full [length] for [Nathan] Lyon, and he's like, 'What do I need to do here?'" Ronchi said.
"'What are my hands doing? What's my body and my head doing? How do I make it work so that I know I can face any ball I need to?' Then it's like, 'I need throws here. I need the flicker here. I need pace on the ball here'. And then he just gets into a zone. He gets into a place... when you see it, you're like, okay, he's ready to bat and bat and bat. If it's at training, I know we're in for a long haul. But if it's in a game, he's zoned in and he's going to do something special against anyone."
While Williamson drives forward in pursuit of becoming a better player, the milestone has caused him to look back momentarily at how far he has come from the first time he walked to the crease in a Test match back in Ahmedabad in 2010.
"I remember walking out and looking around the field and seeing all my heroes," Williamson said. "I used to love playing backyard cricket as a youngster, and all those guys were in that team that I would try and select. It was Tendulkar and Laxman and Dravid, and it was kind of like, 'How am I here? I'd better start watching the ball and try and compete'.
"It was quite surreal. I remember being quite eager to try and get into the opposition's dressing room and chat to some of those guys if I could. Then a few grey hairs later and [after] a number of different experiences over that time, there's not been many days - probably any - where I haven't tried to improve and get better as a player.
"It's never a perfect journey. You go through so much. The format of Test cricket in particular really takes you through that. The learning - physically, [and] mentally - the reflection, [and] the memories of almost every Test that when you sit down and dissect it, there's so much that you do recall.
"The Test Championship final [against India in 2021] is something that stands out for a number of different reasons. But it's a journey, and the highlights aren't there without the other. They're all experiences that you value and learn from. To perhaps reflect on hundred of those, it's something I never could have imagined."