Courtois made his debut in Real’s victory over Leganes on Saturday.
“I get on with everyone very well, the communication with the defence is going well, even during the competition,” Het Nieuwsblad quoted Courtois as saying.
“In training, you see that the level is high. I am now experiencing on a daily basis that Sergio Ramos is the best centre-back in the world. The level [at Real Madrid] is higher than at Chelsea.”
Courtois also spoke about the differences between the home stadium of Chelsea and Santiago Bernabeu.
“It’s twice as big, of course, it’s a very different feeling. If you look forward, you only see a wall of people while at Stamford Bridge you can still see the sky or the hotel behind the grandstand,” he said.
“Of course, this was not the first time I’ve played here. I know the language and I know the stadium. The first few minutes [against Leganes], I was stunned, but then I felt right.”