"I would never say never," Kearney says of being an NRL head coach again. "But the last couple of years took its toll not on just me but everything ... my family. It knocked me about, there's no doubt about that. It was quite challenging in terms of trying to overcome that but this is what I love doing, seeing young men develop as footballers.
"There are a number of things I learned about myself and others that will make me a better coach but it was a difficult time. I'm sure there are easier ways to test yourself [as an NRL coach]. I think [being an NRL assistant coach and Kiwis coach] is a better fit. The feedback from staff after last year's Anzac test to this one was totally different. That's the nature of the job."
The Kiwis have developed under Kearney, and there's a sense the World Cup squad will be the strongest they have assembled for quite some time. They have also achieved some memorable victories during his tenure, not least of them the 2008 World Cup and 2010 Four Nations title.
But they are still underachievers. They haven't won the Anzac test since 1998, haven't beaten Australia in nearly three years and had poor Four Nations campaigns in 2009 and 2011. The Kiwis also haven't beaten England in the UK since 2006.
It's part of the reason Kearney wants to continue in the role beyond this year. "It's been at the back of my mind," he says. "The work we've done, and it's not just me, to try to cultivate and build the Kiwi way and what we want to stand for, I don't want to step away from that. The journey is just beginning.
"We want to become a force that's always competing on the world stage and there are a number of Kiwi kids coming through. I want to be able to give them something so they want to play for the black and white jersey."
Retaining the World Cup would make a big difference. The Kiwis open their campaign against Samoa in Warrington on October 28 and will also face France and Papua New Guinea in pool play.
They'll have one warm-up game in the UK, details to be announced next week, after a brief camp in Sydney when the 24-man World Cup squad gathers after the NRL grand final.