Let's be honest Utd's poor start to the season was down to a lot of factors. Fergie was leaving and even though well known was a massive disruption - especially with the speculation raging concerning his replacement.
Fergie sold Stam - not just because of what he wrote in the book and the fact he didn't get it cleared first, or that he embarrassed Fergie with his tapping up comments, but because it broke Utd's dressing room golden rule: you never criticise your team mates in public (Keane may criticise team performances and suggest individual players were not performing, but he never names and shames). Fergie had to restore "law and order" before the rot truly set in.
A number of players: Scholes, Beckham & Giggs were under par in the early part of the season and clearly nervous as to who would replace Fergie (e.g. Beckham wanting to know the new manager's identity before signing a new contract).
Fergie tampered with the tried and tested (and stale imo) formula to create a new Utd style. That was a major disruption to the flow of the team as players adjusted to a new system.
Veron and Blanc needed time to settle.
All of these and more contributed to the collective undermining of confidence in the team. They got distracted, started sluggishly, and took an age to recover. Witness the resurgence when Fergie announced he was staying. Utd went on a run and, almost miraculously, took it the wire.
It's way too simplistic to say it's just the defence's fault. In the same way as saying Rio's arrival will win us everything.
Utd's success has never been about individual genius (though, goodness knows we've witnessed some of those moments over the last decade) or even about work ethic (though that is a renowned Utd trait). It is not even about hunger (and no team has been as ravenous for success as the red devils).
No, what has set Utd apart from every other has been self-belief. The self belief that never knows when it's beaten. The self belief that refuses to lie down. The self-belief that relentlessly claws back a 12 point lead to win the tiltle, or scores a wonder goal in an FA cup final because only that can win the game, or scores twice in injury time in a European Cup final to do what others declared could never be done.
That is the magic of Utd. They dare to believe. They make believers of us too.
That is what was missing in the early part of last season. That is what Fergie and his newly assembled team will be working hard to reclaim.
And when they do...