The Italian led Juventus to three successive Italian top-flight crowns before departing for the Blues last year, where he helped the London giants to the English title at the first time of asking.
However, this time around Chelsea find themselves six points off the pace after seven league games following Saturday’s 1-0 loss to Manchester City, and Conte admits he can already tell the Premier League will prove far more difficult a title to defend.
"We won the title with Juventus and I was expecting a really strong challenge from AC Milan, but instead they sold Zlatan Ibrahimovic and Thiago Silva to Paris St Germain, so they became weaker," said Conte.
"It wasn't simple second time, but it was easier. Here, from last season to this season, you have big teams and now they are bigger.”
He continued: "I think last season we did a really great job because we won the League against a really strong team because Man City last season also was a fantastic team.
"And now after I think a great transfer market, they have improved a lot. It's not simple to play this league. We have to try to do our best in every game with great ambition because we must always have the right ambition.
"But at the same time sometimes you have to compliment your opponent. You must be honest and accept the result."