The Red Devils sit top of the Premier League table with 10 points from their opening four games, while they also made a winning return to the Champions League in midweek with a 3-0 victory over Basel.
United will look to continue their unbeaten start at home to struggling Everton on Sunday, but despite beginning the campaign in promising style, Mourinho insists that it is far too early to draw any conclusions.
"At the team level I am happy. I think after one year we are a different team. Not just because we are playing in the Champions League, which is the competition for Manchester United, but because in the Premier League we managed a good start which put us initially in the top positions in the table," he told Sky Sports News.
"The way we play, the way we think football, the way the fans think, the empathy between the fans and the team, the confidence levels of the players, the footballing level I am happy with what we've done so far.
"[We are] in no position. We have 10 points. Man City have 10 points. Chelsea have nine points, Tottenham maybe seven, Liverpool seven, so what's the difference? One point, two points, three points, one weekend, two weekends. They also have managers with title histories. Not all in the Premier League but in other countries. Everybody has a history of success."
United have kept clean sheets in four of their last five outings.