But as Spurs prepare to face the Gunners at White Hart Lane on Saturday, Comolli revealed: "I saw Arsene after defeat at Arsenal and he didn't talk, he didn't eat.
"Normally - that is to say, when he hadn't lost - he was a nice guy, with a lot of class and restraint.
"But people knew there was this cauldron inside of him.
"Arsene in a rage is nothing like the image the people have of him.
"It is precisely the opposite because he is perceived as detached and lacking passion.
"In fact, he always gives 200 per cent and, yes, he can explode.
"I have seen him in some incredible states. But the amazing thing is that the morning after a defeat, although he feels exactly the same inside, he never shows it to his players."
Comolli's comments are in a new book 'Arsene Wenger, The Biography', written by Xavier Rivoire and published by Aurum.