After rupturing his cruciate ligaments in December 2011, Vidic was nothing more than a bystander last May when United went to Sunderland and had the Premier League title snatched from their grasp with virtually the last kick of the campaign.
As the Red Devils needed to win, and hope Manchester City failed to beat QPR on home soil, Vidic knew it was a long shot, even though they got much closer than anyone could imagine.
However, it is the memory of how an eight-point lead evaporated in the space of just four end-of-season games is seared into Vidic's mind.
It is why there is no sense of satisfaction just yet, even if he accepts a 15-point lead should be enough.
"You are never sure until you have the trophy in your hands," said the Serbian.
"I do think about last season. It is still fresh.
"If we hadn't experienced that people would be saying it is already done.
"But that kind of thing keeps you sharp.
"It is good for the team and the players because we don't want that to happen again.
"It was bad last year but this year it is working for us."
Yet Vidic shares the same sentiments as his manager in finding it difficult to believe United could have established such a position of strength with nine games of the campaign remaining.
"We didn't expect this situation," he said. "No-one expected did.
"We are happy with it but we still have big games to play.
"We have to play City, Arsenal, Chelsea, West Brom, Swansea. They are teams who can hurt you. They are tough games.
"Teams at the top and some who are fighting relegation. We just have to keep winning."
Pressed for the difference between last season and this, Vidic points to an increased goals output.
He also does not underestimate the strength of a squad that would allow Sir Alex Ferguson to field two entirely different teams at Sunderland on Saturday and Chelsea in the FA Cup on Monday should he so wish.
"It is hard to say what the difference has been," said Vidic.
"We have scored a lot of goals. We won more games than any other Manchester United team in the Premier League. That is a statistic you have to respect.
"Also, if you look at the players who have played this season, everyone has their role.
"The manager can rest players. Some have come back from their national teams and now we have two games in three days, but we can still choose two different teams to keep things fresh."