Even those that love Antonio Conte concede that he can be a difficult character to live with.
For many years, his wife has had to put up with her husband waking up in the middle of the night, turning the light on and scribbling down some new tactical idea that has just popped into a brain that seemingly never switches off.
Andrea Pirlo, meanwhile, admitted last year, "I can say that Conte is a genius. But, like all men who possess genius, he is a little mad."
Which would explain why in taking on Chelsea over player recruitment, he has picked another fight that he cannot win.
Conte did the same thing at former club Juventus just under four years ago, when he sensationally resigned after totally transforming the fortunes of a club coming off successive seventh-placed finishes in Serie A by leading it to three consecutive Scudetti.
However, behind the scenes, all was not well. Conte was clashing with his bosses on a regular basis. He was even at odds with them over their pre-season programme but transfers were the heart of the issue.
Disappointed by a dismal group-stage exit from the 2013-14 Champions League, Conte wanted Juve to spend big that summer, and had his sights set on Alexis Sanchez and Juan Cuadrado.
Juve instead spent just €28.5 million, on six players, two of which (Patrice Evra and Kingsley Coman) were free, while he was given no assurances on whether Arturo Vidal and Paul Pogba would still be in Turin when the transfer window closed.
Juve's prudence bitterly frustrated Conte, who when asked about his team's Champions League prospects, memorably moaned, "You cannot eat in a €100 restaurant with just €10 in your pocket."
He even threatened to quit at the end of the season but was talked into taking some time to think things through during the summer holidays by Bianconeri director Pavel Nedved.
The arguments continued when he returned, though, and he walked just two days into pre-season.
"Antonio has resigned because he did not have the energy to continue disagreements with management," Nedved admitted.
Four years on, he now finds himself in the same situation, with Chelsea owner Roman Abramovich and recruitment chief Marina Granovskaia having grown increasingly irritated by Conte’s public complaints about the club’s inability to compete with Europe’s elite in the transfer market.
On paper, he has been well backed financially, for the second consecutive window, having been allowed to bring in Olivier Giroud, Emerson Palmieri and Ross Barkley in January alone.
However, from Conte's perspective, he feels that he has not been given the money to sign the players that he wants, world-class talents that will improve his first 11, not just strengthen his squad.
Chelsea's parsimony, founded on the club's desire to become self-sustainable rather than remain reliant on Abramovich's deep pockets, was never going to sit well with a man like Conte, who is so obsessed with winning that he even named his daughter Vittoria.
By telling Diego Costa that he had no future at Stamford Bridge via text message, Conte also made problems for himself in the dressing room but, again, that was totally in keeping with his aggressive character.
This is a man who actively seeks out confrontation, believing that it can actually benefit a team in terms of concentration.
Indeed, ahead of Juve's final game of the 2013-14 season, against Cagliari, Conte was so desperate to see his side maintain their focus and claim a victory that would allow them to become the first Serie A side to break the 100-point barrier, that he manufactured a row with his captain, Gianluigi Buffon, over player bonuses in front of all of the entire squad.
According to the book ' Metodo Conte ', the coach shouted: "Shut the f*** up, Gigi, what the f*** are you saying?! Don’t say a word!
"I don’t want to see you anymore; get out of here! I would have never have expected it from you!
"You don’t know s*** Gigi, you are the captain, you are a disappointment to me as well as all these idiots."
Buffon went along with it, the players bought it and went out the following day and beat Cagliari 3-0 to end their campaign on a record-breaking high.
However, Conte's increasingly tense tenure had already become unsustainable.
He had fallen out with Juve's director of communications, Claudio Albanese, while his relationship with club president Andrea Agnelli had become increasingly strained.
When later asked if Conte had a weakness, Agnelli replied, "He is perhaps a bit touchy, especially when you tell him that something isn’t going the way he wants it to."
Chelsea's season certainly isn't going the way Conte wants right now, his dissatisfaction has overshadowed the club's entire campaign and it now feels like just a matter of time before he once again grows "tired" of fighting with his bosses – or they grow tired of him.
As he knows full well, there is only ever one winner in such arguments – and it's never the coach.