The Serbia international revealed that one of the reasons he decided to move to Old Trafford this summer was Mourinho's presence at the club.
"Mourinho is a brand, and the best coach I've ever worked with," the defensive midfielder said. "Sometimes it isn't easy to work with him, because he always demands more.
"Even when you play the best match in your career, he considers that you can play better in the next match."
Since his £35m move to Manchester United from Premier League rivals Chelsea in the summer, Matic has thrived under his Portuguese boss and continued his fine start to the season with a dominant display in midfield as United overcame Benfica 1-0 in the Champions League on Wednesday.
The pair won the Premier League two years ago during their time together and Chelsea and Matic is still full of praise for the manager.
"Privately he's completely different from the way he is perceived by the general public," he said. "This is a man who possesses all human virtues. He's not at all cold or conceited, as he is presented in the media.
"He has created an excellent group of players with huge potential, and everything is there for us to achieve good results."