"I know the club, the players and the coaching staff, and my Spanish is better," Courtois told El Mundo Deportivo.
"The first few months were tough and then I adapted well. I wanted to stay here another year. Chelsea knew that. I had no doubt in my mind, I was completely clear and very happy that is all came through as I wanted.
"It could be that Atletico ask me to stay another year. I am very happy here and if I stay for one, two or ten more years I will be very happy. I don't know what will happen."