Mourinho is back in England for tonight's Champions League tie at Manchester City.
He said: "La Liga is la Liga and the Premier League is the Premier League. They have different cultures. The Spanish league has three teams who are a fair way ahead of the others, but in England it is a more competitive league. I have been lucky enough in my career to be in all the important footballing countries and I have improved as a coach.
"After so much experience it is important to sit down and evaluate what you have been through to see where you are happiest."