The Liga champions' president has voiced his opinion that the former Inter boss has at last become used to the pressure of working at los Blancos
The Portuguese trainer joined Madrid from Inter in the summer of 2010 and initially struggled to cope with the fans' critical attitude toward the team.
However, Perez believes Mourinho now understands that the expectations at los Blancos are sky-high.
"Mourinho has taken a while to understand what Real Madrid is about. He was surprised by the club, the people and the fact that the fans whistle at the players and at him," Perez stated at the club's Assembly.
"He emphasised the fact that he had been at several clubs, in Portugal, Italy and England, but I told him that this is Real Madrid. A truly unique club.
"The club's expectations are much higher than those of other clubs and if things don't go to plan on the pitch, the fans start to whistle. Some players who have come here have failed to understand this concept."
Real Madrid are currently preparing for Sunday's Liga match at home against Deportivo La Coruna.