Sir Alex Ferguson sends Manchester United into battle on Monday knowing he is attempting to condemn Manchester City fans to the worst day of their lives.
Ferguson has opted to take United out of Manchester for the build-up, instead heading to South Wales at a bolt hole near Cardiff to escape the attention. He knows how many cameras are going to be lurking, trying to get a thought or a prediction about what he has already stated will be the biggest Manchester derby ever.
"It means everything to a supporter. It is everything," said Ferguson. "For both sets of supporters, going to work on Tuesday will be the most important day of their lives. People have been brought up to be what they are through their fathers and their grandfathers and grandmothers. You can't change a family's traits."
He added: "I saw a banner at Ibrox recently that said 'supporting Rangers for 139 years'. That sums it up. It is in the blood of the supporters and I know a lot of our supporters who would give everything to win this game on Monday."
The local paper has published a map of the strongholds for both United and City within the Manchester boundaries, which have quickly been disputed.
It is pointless anyway. On streets and even individual houses, there can be red and blue, both of whom have felt the title was won at points this season, and also believing it had been lost.
That is why Ferguson accepts the campaign will be tinged with regret for one as the other celebrates their triumph.
"If one loses they will be reflecting on what might have been," said Ferguson. "The points total which both teams will probably amass, it is championship form.
"But it will be tinged with regret simply because it is the derby thing. You can't get away from it. It is our fans' most bitter rivals.
"For me it is just another league game. For the supporters it is special."