Facing the media for the first time since returning to Stamford Bridge, the 50-year-old Mourinho stressed he is "calmer" figure transformed from the fiery incarnation who hastily left six years ago.
"I am better able to manage my emotions, calmer in victory, less depressed in defeat," Mourinho told more than 200 reporters inside Stamford Bridge.
"I'm humble," he added. "Sometimes it doesn't look like I am, but I am."
When Mourinho was first hired by Chelsea in 2004, he described himself as a "Special One," and immediately produced two Premier League titles.
On Monday, he simply declared: "I am the Happy One."
The Portuguese feels like he is back among friends, having spent recent months declaring his enduring affection for Chelsea as fans demanded for his return while jeering interim manager Rafa Bentiez.
"It's the first time I arrive in a club where I already love the club," Mourinho said.
Any bold declarations of intent were avoided in the glare of dozens of flashbulbs. The main mission is simply to qualify for the Champions League by securing a top-four Premier League finish. The trophies come next.
No longer is the Champions League the priority, after European football's top prize was finally delivered in 2012 by Roberto Di Matteo — one of seven managers at Chelsea since Mourinho's three-year reign ended abruptly.
"We are ready to work together and (have) much better conditions this time to succeed and have what this club wants, which is stability," Mourinho said.
"Stability" was a word repeated several times during a 50-minute exchange with the media, and Mourinho has a four-year contract to back it up.
There also appeared to be a partial re-writing of history Monday over the terms of his split with owner Roman Abramovich in 2007.
"I read ... we had a complete break of relationships. That was not true," Mourinho said. "Many people didn't believe in that, but it was mutual agreement. At the time we thought it was best for both of us — me and the club. It was a sad moment."
The Chelsea statement in September 2007, however, emphasized that the "relationship between the club and Jose had broken down."
Mourinho insisted that he is back at Chelsea not because he was overlooked for jobs at the Manchester United or Manchester City.
"I am where I want to be ... and it was a job I was offered," Mourinho said.
Mourinho has spent the intervening years at Inter Milan and Real Madrid, the last of which ended earlier this month following a three-season reign after falling out with the team's fans and parts of the hierarchy.
Responding to claims by Barcelona star Andres Iniesta that his combative managerial style harmed La Liga, Mourinho said: "I damaged Spanish football by being the manager that broke Barcelona's dominance."
Chelsea offers Mourinho the platform to re-establish his supremacy in management after a trophyless final season at Madrid.
Mourinho led Chelsea to its first league title in 50 years in 2005 and then successfully defended it the following season, while also winning the FA Cup and two League Cups.
"I want to be respected for what I did in the past for this club, but I want to be loved for what I can do from now," he said. "The club knows my mentality, my nature, and the fans can be sure I come here to give my best and to try and reach success."
Mourinho failed to win the Champions League so cherished by Abramovich during his first stint at Chelsea.
But Europe's top prize, which Mourinho won at FC Porto in 2004 and Inter Milan in 2010, was delivered to Chelsea by Di Matteo.
"(The) Champions League cannot be an obsession for me because I was happy to win it twice," Mourinho said. "I don't think it's an obsession for Chelsea because Chelsea has won it."
Mourinho is returning to a very different Premier League.
Champion Manchester United will be without Alex Ferguson in the dugout next season for the first time since 1986, with David Moyes replacing the retiring Scot.
And Manchester City has emerged as a force — on the back of the kind of investment from Abu Dhabi since 2008 that Chelsea enjoyed after Abramovich's 2003 takeover.
"In 2004, Arsenal were the power," Mourinho said. "They'd won the league without losing and were an absolutely fantastic team, and us and United were trying to go there. Now the picture is different."
Despite Benitez's acrimonious reign from November to May, he still won the Europa League and secured Champions League football for next season, setting the bar high for Mourinho.
"The expectations are higher because people know what I can deliver," Mourinho said. "At 50, I think I'm still very young as a manager ... I'm the same personality, same nature, but a different perspective."
Rob Harris can be reached at http://twitter.com/RobHarris