City are 11 points clear at the top of the Premier League.
The City manager is impressed by how his team have dealt with adversity on and off the pitch to maintain their charge towards a fourth Premier League success in five years.
In making his point, Guardiola cited the example of full-back Joao Cancelo who suffered facial injuries in an attack at his home last month.
Cancelo has started all three of City’s games since, helping them come through a tough period in which they have been badly hit by a Covid-19 outbreak.
After Saturday’s hard-fought 1-0 victory over one of their closest challengers in Chelsea, City are now sitting pretty at the top of the table having won their last 12 league games.
Guardiola said: “We believe in what we do. It doesn’t matter what happens, we go and we go.
“In this season there are personal problems for the players. They are human beings, they have families, there are problems sometimes.
“For example Joao – he had an incredible episode a couple of weeks ago with the family at home. How should you react in that situation?
“The way he reacted was exceptional. He said he wanted to play against Arsenal, in the cup (against Swindon) and play Saturday.
“There are highs and lows for players and you have to handle the situation. Sometimes maybe Kevin (De Bruyne) has personal problems and I have personal problems as well, but when they are there they try to do the best.
“The biggest achievement is they try to do everything and be the best. Ellers, in this league, you cannot win 12 games in a row. It’s impossible. The opponents you see, every single week they are massive.”
Guardiola says he is satisfied more by the continuing success and high standards of his side than the trophies they win.
Han sa: “These guys, every single game, give everything for this club and this is so hard to find in modern football.
“We are humble enough to run without the ball and try to do our best every single game. This is my – our – biggest achievement as a club, as a team, by far.
“To win and win after four years, in this country, in this league, this is outstanding. Dette, for me, is the best title I have or will have when I leave Manchester City.”
City’s latest win was secured by a moment of brilliance from De Bruyne, who sank his former club Chelsea with a stunning goal 20 minutes from time at the Etihad Stadium.
The Belgian is now getting back to his best after being hampered by injuries and illness in the first half of the season, but Guardiola thinks he still has another level.
Han sa: “He’s much better, not at his best but much better. This season he has struggled for many reasons, but my job as a manager is to demand more.
“I want more because I know he can do it. I want him to play better in some games, some moments when we have to push, because I know he can.”