The Portuguese has been officially unveiled at Stamford Bridge for a second spell at the west London outfit, describing himself as "very happy" at a club he already loves
The Portuguese was confirmed as Rafael Benitez's successor last Tuesday to bring to light one of the game's worst kept secrets.
And Mourinho, who was accused of having "damaged" Spanish football by Barcelona midfielder Xavi Iniesta on Sunday, says his return to the team he won two Premier League titles with was an easy decision due to his love for the club.
"I'm the happy one. Time flies. It looks like it was a couple of days ago but it was nine years ago and since then a lot of things have happened in my professional life," he told reporters.
"I have the same nature. I have the same person. I have the same heart. I have the same kind of emotions related to my passion for football and for my job. But of course I am a different person.
"I describe myself as a very happy person and it is the first time I have arrived at a club where I am already loved. [Usually] I arrive and have to build emotional relations and know how to love the club after some time there.
"This time is a new kind of feeling because this is the first time I am arriving to a club and I love it. I love it already."
Mourinho guided Chelsea to a first top-flight title success in his debut season in 2004-05, breaking a number of English football records in the process including a 95-point haul and just 15 goals conceded.
The 50-year-old added a second title the following term, and ended up with six pieces of silverware come his departure in September 2007, but he is now aiming to better that haul upon confirmation of his new four-year stay.
"In football you never know but I want to believe it's possible," he continued. "I always trust my work. In this case I know many of the people at the club and the kind of mentality and ambition people have.
"My career was built and raised on success. I was able to reach success and win trophies and to leave different kinds of legacy. So I have to believe, and that's a normal message I give my players; work hard, work with quality.
"The club is much more important than ourselves. We are nobody compared with the club. And, of course, working well, normally brings success."
Mourinho was sure to dismiss rumours regarding the sudden end to his first tenure, insisting the decision was mutual between himself and owner Roman Abramovich with no break down in relations.
The former Real Madrid and Inter manager does, though, feel the events of six years ago has paved the way for his return.
"That's not true. As a start, that's not true," he replied when questioned on a tense relationship with Abramovich. "I read and I keep listening that I was fired, I was sacked, we had a complete break up of relationships... that was not true. Many people won't believe, but it was a mutual agreement. At the time we thought that was the best for both of us; for me and for the club.
"Of course it was a sad moment but I don't regret that decision because after that I went to Inter, where I had probably the best moment of my career and after that I went to Madrid, where we have still the record of the best team in Spanish history. After that, Chelsea became European champions for the first time.
"I think it was a difficult decision for both of us at the time, but a decision made by mutual agreement. It would be impossible for me to be here today if we had no relationship.
"I think we [Mourinho and Chelsea] are in the best moments of our career, if you can call it that, and ready to work together again in much better conditions. We have what this club wants, which is stability."