"You go to work some days and you get up and you don't fire. That's what happened to us, for whatever reason."
Changing to a hushed voice, he spelled out what the Warriors needed to change from their last grand final appearance.
"Keep our feet on the ground, don't get our heads up our ass, and don't leave the game in the changing room."
In Sydney before Sunday's match, Sir Peter said the chatter on the streets was mostly, often reluctantly in favour of the Warriors side.
"We were superb in Melbourne ... and people were paying tribute to us left, right and centre. People that didn't even like us said 'what a great game'."
A working class champion - "a butcher, not a businessman" - Sir Peter has insisted that he and Prime Minister John Key sit together in the stands at ANZ Stadium, instead of a corporate box.
He has warned Mr Key of the likelihood of colourful language.
The grand final marks another high point for the Mad Butcher, who after investing his money and enthusiasm in league has become synonymous with the Warriors brand.
He sold his chain of 37 butcheries in 2007, but has retained the moniker and his connection to the game.
Despite years of backing the Warriors - he has missed only two games at Mt Smart since 1995 - he said he would claim only a smile if they won on Sunday.
"There are many people just as keen and supportive of the team as me. Those people that come up every week from Timaru, from Christchurch.
"If we win, I will have a little smirk because yes, I'm part of the team. But that's all, I'm just a part of the team. I'll certainly take no credit, I'll just be proud to be on the boat with the boys."