"It's just another run," batting coach Luke Ronchi said of Williamson's approach.
Indeed, it looks at times as if Williamson needs to be reminded to raise his bat when he reaches milestones, such is the tunnel vision he brings to his work, which also happens to be his pleasure.
"He just loves batting. He clicks into gear early on in the day when he's warming up and you can just see it," Ronchi said. "You look at him and you know he's going through stuff in his mind and then it's just him being him out there. He's in his own little world."
To put it another way: it's Kane's world and we're all just living in it.
Williamson finished day two unbeaten on 112, having shared an unbroken partnership of 215 with Henry Nicholls (89). It followed his scores of 251 against the West Indies in Hamilton and 129 against Pakistan last week.
It was Williamson's 24th test century, putting him alongside legends of yesteryear Sir Viv Richards, Greg Chappell and Mohammad Yousuf, and Sunrisers Hyderabad teammate David Warner.
Only 22 players have scored more test tons and Williamson has no plans to stop soon.
It was his first century at Hagley Oval, the only New Zealand ground where he has struggled, with an average of 28 before today – anaemic by his lofty standards.
Nicholls will start tomorrow in sight of his seventh century, which would put him level with Glenn Turner, Andrew Jones and Bevan Congdon.
Both batsmen got a big assist from Pakistan captain Mohammad Rizwan, who bowled part-timers in the period just before tea.
"If you look at the way the day panned out, if you look at that little period, it changed the momentum of the day," Ronchi said. "It allowed Kane and Henry to kick it into gear in that final session, when they were brilliant."
Pakistan seamer Mohammad Abbas was left to rue the missed chances.
"If you drop a catch in test cricket it's very costly," he said of chances spilled of both unbeaten batsmen.
"We had plans [to Williamson] but he's a world-class player."
