The Portuguese coach was announced as Tottenham’s new manager on Wednesday morning following the departure of Mauricio Pochettino.
Mourinho was facing the media for the first as the manager of Tottenham Hotspur, and has pledged not to repeat the similar mistakes he made during his time at Old Trafford and Stamford Bridge.
"You never lose your DNA, your identity, you are what you are, the good things and bad,” the 56-year-old told the media
“Don't ask me what the mistakes are but I realised I made mistakes and I'm not going to make the same mistakes. I'll make new mistakes but not the same.”
The former FC Porto boss was asked if he has improved after his brief time out of management, and he quickly revealed what he did when he was out of football.
He added: "I believe so. I always thought the 11 months wasn't a waste of time - I was to think, to analyze, to prepare, to anticipate things.”
"I'm relaxed, motivated and ready, and I think the players have felt that in the two days. This is about Tottenham, it's not about me.”
“You go through periods in life and in this period it's not about me - it's about the club, the players and the fans, and I'm here to help them."
Mourinho has insisted that he does not need new signings, as he is happy to work with the available ones.
"The best gift for me. I don't need players. I am happy with the ones I have. I just need more time with them. I know them well from playing against them, but you never know them well enough.”