The Spanish champions have not enjoyed the best start to their campaign and enter the first Clasico of the league season this Sunday eight points behind their Catalan rivals who sit atop of the standings.
“When Madrid plays Barcelona, the world stops,” he told Bein Sport.
“It is a game we love to play and it is not just us, but, surely for them also. In this sense, it is definitely more than a normal league match.
“But our goal is to win the championship. It is just three points in the end.”
The former Inter coach believes the champions tag is contributing towards his side's indifferent start to the Primera Division.
He added: “The fundamental difference is this team last season were not champions. This season they and in my opinion, the team has started the season this way because of the prestige of being the defending champions."
Mourinho was then asked to reveal what he thought about Real Madrid's chances in this year's Champions League.
"The Champions League? It depends, it is a competition where the difference between winning and losing is very small," he said.
"I do not believe that anybody thought that Chelsea last season would have won it. But, they did and I was happy because I have a blue heart.
"It is necessary that we make it to the quarter-finals or semi-finals. And then from there, anything can happen."
The Portuguese then spoke about Karim Benzema and revealed his happiness at Real Madrid before once again admitting that his desire is to return to England.
He continued: “I am happy and want to continue here. I've signed with Real Madrid for another four years, because we are the world's best football club.
“Following my triumphs in England and Italy, Madrid was missing from my CV. Now that I have it, I have to work to the best of my abilities.
“I was very happy in London though, and I'll return.”