When Mourinho first went to Chelsea standard of "success" was a decent cup run and maybe beating Spurs or the Gunners, consistently winning and playing attractive football wasn't part of the fans expectations. With the personnel he had available it was it was a more straight forward task to put up a wall of defenders in front of Cech and play long ball to Drogba. It got them victories and the fans where happy. However the owner wanted to continue winning and do it with style, and because he was signing the check Roman wanted to say who needed to be brought in and who should be playing. For a control freak like Mourinho there was no way that was going to end well.
During Mourinho's stay at Real Madrid he had the personnel where he didn't have to play total defense to win games. His teams played wide open attacking, his only problem at RM was that Barcelona where much better at wide open attacking football than his team was a Real Madrid fans and management cannot abide being second to Barcelona.
On his return to Chelsea he inherited a lot of attacking talent who were hungry to prove just how good they could be. They started the season off scoring goals for fun, by the end of the Christmas schedule he realized that he could play defense and pretty much coast to the title - similar to what Sir Alex had done in his last season. By the second season the players wanted a different way of winning than what Mourinho wanted, more importantly the owner wanted a different way of winning. This conflict was't going to end well either.
Even before Sir Alex left I believe Mourinho was setting hisself to take over at United and was shocked (and probably pissed) when Moyes and Van Gaal got the nod ahead of him. The squad he inherited was not a bad squad, rather they where being asked to play a style of football that totally did not suit them, the only player that flourished under Van Gaal's style was Mike Smalling and who knows where he is now. Mourinho was smart enough to know that winning alone would not be enough for most United fans, especially after the prior two years of dire football. It took Mourinho awhile to determine his best combination that cold play solid defense and attacking open football but from real early on I felt that Mourinho had the United trait of never giving up on a game - we don't lose we just run out of time.
Mourinho is a Red Devil.
I can't believe it. I can't believe it. Football. Bloody hell.