Sir Alex Ferguson has revealed his incredible will to win boils down to a desperation not to let Manchester United's fans down.[LNB] On November 6, Ferguson will complete 25 years as United manager.[LNB]It is hard to imagine the achievement ever being surpassed in an era where some of his rivals do not even manage 25 games in their job.[LNB]Ferguson's longevity is the product of two things.[LNB]Firstly his success. With 12 Premier League titles, two European Cups and countless other trophies, the past quarter of a century has been the most successful in United's history.[LNB]However, that alone could not sustain him in such an intense job for so long without an insatiable desire for more.[LNB]"The expectation of the club keeps me motivated," said the Scot. "We never want to let ourselves down because of that.[LNB]"Every season is the same. A couple of weeks after the season is over you find out what the fixtures are.[LNB]"You look at the first one, and think that is a hard game. Then you look at the next, and the next. Then you see the Christmas fixtures. You think 'crumbs, we might end up with no points'."[LNB]Ferguson is not being serious in the sense of imagining his team will exit the Christmas programme with a completely blank record. However, it is a recognition that he will never be satisfied, no matter how much silverware surrounds him.[LNB]"The thing that keeps you young is young people," he said. "It is good having young people around you.[LNB]"Last season our youth team won the Youth Cup. It created a great excitement at Manchester United.[LNB]"A lot of first team players came to the final because they love to see the young players progressing too and there are two or three in that team who will do very well."[LNB]It is a template that has brought so much down the years, Ferguson has no need to change.[LNB]While discussions among supporters and the media will continue about the potential for landing Wesley Sneijder, Ferguson is the one person it can be guaranteed will not panic if he fails to secure the Dutch playmaker as Paul Scholes' replacement.[LNB]It was the same when Mesut Ozil went to Real Madrid 12 months ago when United appeared to be leading the chase.[LNB]In 2003, Ferguson was heading out on tour to the United States when he learned Ronaldinho had slipped through his fingers.[LNB]Within weeks he was signing an 18-year-old Cristiano Ronaldo and though it may have taken a bit of time, the former world player of the year went on to secure his place in United's history in a more indelible manner than the Brazilian was ever likely to.[LNB]"We have signed three players - David de Gea, Phil Jones and Ashley Young - and we are very comfortable with that," said Ferguson.[LNB]"We have filled the gaps we needed to fill and we also have players coming back from loan like Danny Welbeck, Tom Cleverley and Mame Biram Diouf.[LNB]"The one area we are having difficulty with is finding someone to replace Paul Scholes.[LNB]"That would be a very difficult thing to do in any event and at the moment there is nothing to report."[LNB]The odds remain on United finding an alternative for Scholes.[LNB]However, if it does not happen, there will be no knee-jerk reaction, the kind of response Chelsea would be famous for given Andre Villas Boas has just become their 14th manager of Ferguson's reign.[LNB]"The kind of league we are in, I have no particular feeling about any manager," shrugged Ferguson.[LNB]"We all have our jobs to do. We try to win. That is the important thing.[LNB]"Chelsea have been our main challengers for years now. We have had some fantastic battles.[LNB]"They have had a few managers and I have got on well with them all. That stays in place."