Mourinho also went on a 12-minute rant 24 hours prior when outlining his past managerial achievements, having seen his side exit the Champions League with a shock defeat to Sevilla earlier in the week.
United midfielder Matic admits that the former Real Madrid and Chelsea manager's high standards can make him difficult to work with, but understands that it is a prerequisite to success.
"I didn't have many managers in my life. He is special because he wants to win always," he told reporters after the win against Brighton. "You can see when we lose a game he cannot accept that. Probably that's why he won more than 20 trophies in his life.
"It is very difficult to work with him because he always wants more and more. Even if you win the league he wants to win again next season. At this high level, Manchester United and where I used to play Chelsea, the players need to be ready for that because the pressure is big.
"Everyone expects you to win every game. Obviously it is not possible, but supporters always expect. It doesn't matter if you are tired or not, supporters want high quality football. It is normal."
Mourinho has picked Matic on 40 occasions in all competitions since signing the Serbia international from Chelsea last summer.