"Genuinely, any one of five or six countries could win it," he says. "Everyone says New Zealand, but maybe because I'm too close I can see flaws. You can't rule out Australia. I've got Ireland down as my wild cards, I think they could easily make a semifinal. Here's how tight it is, you can't even rule out England."
Not that Brooke has anything against England. He has lived in this country for the past 17 years since he came over to play for Harlequins soon after turning professional. He has established a number of businesses here and all six of his children were born in England.
He even suggests that if his rugby-mad sons - or daughters - were to play for the country of their birth rather than for New Zealand, it would be the proudest moment of his life.
His point is, rather, that this is as competitive and hard to call a tournament as has been staged in Rugby World Cup history. As a result, he says: "It's going to be brilliant. I think England will host a great World Cup. Though there is one thing: you want everyone to be talking about it.
"So I really hope England get out of the pool of death. It will ruin it if [they] don't. It will be a real downer."
Brooke knows all about delivering a downer to English hopes. The World Cup semifinal of 1995 is now largely remembered for Jonah Lomu's devastating haul of four tries, flattening England in his path.
But it was Brooke who demonstrated most accurately the gulf in imagination between the two sides when he fired in a dropped goal of stunning audacity. It was astonishing enough to see a No 8 dropping a goal. But Brooke kicked from just inside the halfway line, his effort travelling 47m to bisect the posts. He seemed to be playing a different game from any of those dressed in white. And it was a moment, he says, that was more than 20 years in the making.
"We were farm boys," he recalls of his upbringing in Waiuku with his five brothers, one of whom, Robin, played alongside him in the All Black pack in that 1995 semifinal.
"My rugby skills came from the farm. We had a front yard that was 25 acres. We played rugby golf round the yard. Instead of hitting a ball with a club, you had to kick it into the holes. You really had to manipulate that ball round the course.
"People ask me about '95, was that part of a plan? There was no plan on dropped goals, I just went back to rugby golf.
"The ball came to me, and it was like I was back at home, in the yard, I just hit the thing. People said how on earth does a No 8 drop a goal from 47m? Well, he spends his childhood playing rugby golf."
There is a hint of what it must have been like on the family farm in the garden of Brooke's home near Maidenhead. The grass is littered with balls of every shape and kind.
There are golf balls, tennis balls, footballs and a couple of basketballs. Plus an oval ball decorated with an All Black fern which he picks up and deftly drop kicks over the fence into his extensive paddock, where he has mown a family cricket pitch.
"Actually I was aiming to put it through the slats in the fence," he says. "Need to work on that."
Then he grabs a golf club and fires a couple of balls lying on the grass off into the distance. Then he and his youngest daughter engage in a kickaround with a football, her accuracy with a pass clearly genetic.
"It was never our intention to have six kids," he says of his and his wife Ali's life plans. "But I love it. They're all characters. Very funny, all sporty. And wilful. Boy, are they wilful."
His two sons are, as he speaks, off at a pre-season rugby training camp. And he says he would love it if either of them took up the sport as a living. Not that he would advise them to do so had things not improved greatly since he turned pro in the mid-90s.
"Professionalism in those early days was so shambolic," he recalls.
"I played my first game for Auckland Blues without insurance. There'd been so much messing about with the contract, I hadn't signed it, so I wasn't covered.
"When I arrived at Quins it was into the teeth of a strike. I found it so bizarre when we finally got going. All that time on my hands. Weird."
Before turning professional, he had worked in construction, running a building firm with one of his brothers. They would work all day then train in the evening.
After he arrived in England he yearned for something to do to fill all the spare time he suddenly had on his hands. And he quickly found it.
"I got made player coach at Quins in that first season," he recalls.
"If I had my time again, no way I'd do it. When I should have been rehabbing I was watching videos of the next opponent, or I was in a board meeting, or I was talking to sponsors.
"Also, I actually found it hard to stand to one side telling people what to do then get the energy up enough to do it myself. I knew what was coming, I was setting the boundaries ... and I didn't want to. I lost my appetite, lost my spark."
However, his enthusiasm for the idea of taking charge of a team has returned. He would like to give the coaching another go, he reveals, now that - at 50 - he would no longer be obliged to combine it with playing. "I'd love to coach. But I don't want to make decisions for financial reasons. I want to make decisions on the pitch for the right reasons, because it's calculated. The right thing to do. Not because I need to keep the job."
So instead of returning to the dugout, he runs his own business. After a serious setback in the downturn that affected the building trade after the 2008 crash, one which plunged him close to penury, he has re-established himself with a highly successful recruitment business supplying workers to construction projects such as Crossrail.
Called Number 8, it is a reflection of his time as the finest in the world at running a game from the back of the scrum.
"I was different off the base, I could back myself to get things moving," he says. "One thing I am a little bit apprehensive about the modern game is that because of the attention to detail things are getting a little robotic. We don't see so many spontaneous moves off the back of the scrum. Like footballers, the priority seems to be to look to milk penalties. I fear that instead of being a great attacking weapon, the scrum is coming to be seen as just the way to get yourself three points.
"I'm really hoping in this World Cup the likes of Louis Picamoles, Kieran Reid, Ben Morgan prove me wrong. And we see a No 8 do something different."
Like scoring a dropped goal from 47m. "That would be great wouldn't it?" Brooke says with a smile. "I'd like to see that." Wouldn't we all.
