City became only the second English team to win the Premier League, FA Cup and Champions League in the same season in 2022/23.
And the Blues’ boss has tempered expectations that his players will achieve such a monumental height again this campaign.
“It is impossible to do what we did last season,” said Guardiola.
“It’s once in a lifetime, I said to the players forget it, we climbed the highest mountain but now we come down the mountain and we start from there with everyone with the same intention.
“It will be difficult to climb as high as possible and we will see our football, our behaviours, our mentality, will dictate how the season will be.
“Football and sport, what we’ve done will remain in our hearts and minds but it’s over.
“Every season we start from zero again, but our history speaks for itself. It’s almost impossible to repeat, we’re aware but we know how difficult it was and will try to do a good performance against Burnley, and after Newcastle then Sheffield United and game by game.”
City begin the defence of the Premier League title against Burnley on Friday evening.
Guardiola believes Vincent Kompany’s side will be incredibly tough to beat after the Clarets’ record-breaking Championship campaign and warns that playing sides who have just won promotion early can be dangerous.
“Normally, the first games are difficult,” he said.
“Especially against newly-promoted teams because they have nothing to lose, they have the energy and the dream for a good season.
“Vinny knows us well and has done an incredible job, changing the way Burnley played for the last few years with Sean Dyche.
“He destroyed the Championship, since day one it was win, win, win and it’s so difficult in this competition - he’s done an incredible job.
“So with the style from Vinny, it will be a tough game, especially at the beginning, it’s so difficult.
“You sometimes need time to reset, but we have to come back the way we were. It’s a question of time.”
