WENGER: IT'S SO HARD TO HIDE MY FEELINGS.
Wenger, the studious, bespectacled Arsenal coach, says he was once a hothead who was even sent off for berating a referee from the bench.
That will be a major surprise to fans who have been astonished by Wenger's calm, clinical approach to his job.
Frenchman Wenger is something new in the hothouse world of English football - and, unlike just about every other boss, hasn't blown his top once in his 13 months at Highbury. There couldn't be a greater contrast with fiery Alex Ferguson, even if Fergie has mellowed since the pots started rolling in to Old Trafford.
Wenger gave a unique insight into his unique character as he prepared for today's clash with Manchester United. It's a game which could test his temperament to the limit.
Wenger said: "I am not always like I look. But I am conscious of the fact that I have to keep the lid on.
"It's one of my responsibilities to not show too much of what I feel.
"It is a basic rule of the job never to react when you are upset. But it is a difficult thing for me. The easy thing is to shout a lot.
"When I started, I was very emotional. I made many mistakes by reacting to things too quickly. I was sent off when I was manager of Monaco for shouting at the referee.
"Afterwards, you're so sorry. You realise you've done so much damage you cannot repair. You spend so much energy trying to repair those mistakes when the main thing is to understand what's really important.
"It helped me a lot to go to Japan, where I was manager of Grampus Eight. Everybody there is controlled. They laugh at you if you show emotion."
Players who regularly dodge teacups flung by irate bosses will be envious to learn that Wenger doesn't even hammer his team.
He said: "I am angry in the dressing-room sometimes but I don't come out with my angry side. I show the same behaviour with the players I show in public."
Don't get the wrong idea about Wenger. He is not a robot and his passion for football runs deep.
He admits he fumed on Wednesday as he watched United's Dennis Irwin axed by a hatchet-man from Feyenoord. "You cannot love the game and accept something like that," he said.
He is also aware that the intensity of the game here can breach the most firm of mental defences.
Ruud Gullit, Chelsea's laid-back boss, has been yelling from touchlines this season when last term he hardly ever stirred from his bench.
"Wait until you see him in six months' time," joked Wenger. "The game here is the most emotionally intense of all. When you start at a club, you have a distance. The more you get involved, the more you have intense reactions. The job penetrates you.
"I don't say I have mastered it completely, although I haven't done anything I regret since I came to Arsenal.
"But I cannot give any guarantees. I may even run on the pitch today to tackle somebody."