The coaching great took the Benfica job barely a week after being sacked by Fenerbahce.
"If I had stayed at home until the end of the season, I would have earned more than working at Benfica," he said in response to reporters asking him about his earnings.
"I could have done some sightseeing and visited with my family, gone to the Algarve (a region of Portugal). You can't even say I'm here for free.
"I'm here with a negative feeling, because I really enjoy working. I missed playing for the title, which is what Benfica needs to do. This is a great opportunity for me as a coach and as a person," he said.
In short, Mourinho wants to "test himself," taking risks: "I want to be open to victory and defeat: these are things that give me energy, that take me out of my comfort zone."
The journalists present then asked him what the presidents of Sporting and Porto had said to him, wondering whether he would have considered their offer: "The conversation with presidents (Federico) Varandas and (Andres) Villas-Boas was very simple. They said 'good luck, but I hope you finish second.'
"If I had been invited to coach there, I honestly don't know if I would have accepted, but considering how quickly I said yes to Benfica, I'd say no."