Barcelona outplayed United 2-0 in Rome with goals from Samuel Eto'o and Lionel Messi, as United, after a bright start, were totally overwhelmed by the Catalan giants.
After the dust had settled on one of United's worst performances of the season, Ferguson said: "In adversity you always move forward quicker. We're still a young team and we can improve on that. In fairness, we were beaten by the better side. I know what went wrong and it will not happen again."
Ferguson has never explained exactly what he thought did go wrong, but whether United are a better team now than they were in 2009 is a subject that will be debated every day until the final is over.
One thing is certain, they will have to improve on the way they played that night at Rome's Olympic Stadium to lift the European Cup for a fourth time.
To do that against the best club side in the world, they will have to demonstrate the kind of assured authority and confidence they displayed on Wednesday against one of the worst semi-finalists the Champions League has produced.
United sealed their place in this year's final by destroying Schalke 04 4-1 at Old Trafford for a 6-1 aggregate semi-final victory and were never seriously troubled at any time over the two legs.
The team that secured their place at Wembley showed nine changes from the side that won the first leg, and for the final Ferguson could chose 10 of the eleven men who faced Barca in 2009 with only Cristiano Ronaldo of the starting line-up no longer at the club.
There is little that Ferguson or Barca coach Pep Guardiola do not know about each other's teams and while the game is still more than three weeks away with domestic issues still to be settled, the key area, as it was in 2009, will be in midfield.
Then, Barca's Xavi and Andres Iniesta totally dominated Anderson, Michael Carrick and Ryan Giggs and laid the foundation for Barca's success. Ferguson will not want that to happen again.
PERFECT SETTING
Wembley is in many ways the perfect setting for this year's final. Both Manchester United, in 1968 and Barcelona, in 1992, won their first European Cups there and Ferguson believes United will go into the game far better prepared than in any of the previous finals he has lead them into.
Asked if there was a sense of destiny after United won the European Cup for the first time at Wembley in 1968, Ferguson added: "Let's hope so."
"I think it will be a fantastic final. It is some weeks ahead and I hope we have everyone ready," he Sky Sports.
"The big advantage this time as opposed to two of our previous finals is that we have no players missing. In '99 we missed Roy Keane and Paul Scholes and in 2009 we missed Darren Fletcher.
"We've got everyone available this time and that does make a difference.
"This is the best competition in the world, all the best teams are there. To get to the final is an achievement itself, but to win it is the ultimate."
