Losing at Old Trafford carries no shame. Even this season, it's still a very difficult place to go. Just ask Manchester United, who have had to go there six times in the league this season already and only won three of them. A narrow 1-0 defeat can just be taken on the chin and moved on with... ordinarily. But this wasn't an ordinary defeat, because as much as Manchester United won it, Arsenal lost it.
In a sense, it would've been easier to take for Arsenal if they showed up at Old Trafford and encountered a fired-up United side that tore out of the blocks and played like gods, storming to a 4-0 victory. That didn't happen, though. The hosts defended well, but few of their other players were better than average, and generally coasted in the manner of a Ferguson-era United side that was assured of all three points before mid-table teams started smelling blood and going for them. They treated Arsenal like a team that was always going to lie down at Old Trafford. They treated Arsenal like... well, they treated 2013 Arsenal like 2011 Arsenal, and it worked.
That's the big worry for Arsene Wenger - not that his team lost, or didn't play badly, but the manner of the defeat, in a poor game, without offering any real resistance at all. The fact that it resembled similarly meek surrenders against United in recent years gone by, where they'd turn up and lose narrowly if United weren't in the mood, or get clobbered if they were.
Negativity as a result of fear of Arsenal's form probably played a part in how United played, but the lessons for David Moyes were very valuable ones. Phil Jones should be starting in Manchester United's midfield, and whoever his partner is is of secondary importance. That was proved in the preceding games in which Michael Carrick was injured, and when he returned, Jones even managed to do enough running for two, and continued a vital record, once again at odds with Carrick, of performing in the biggest games. That discovery alone could be huge for dragging United back level with their rivals.
Secondly, David Moyes might want to reflect that it was a mistake to drop Adnan Januzaj. The youngster is not simply a good talent who may become a good player if he gets game time - he is one of the club's best players as he is now, and deserves to be starting over pretty much everyone that has featured on the wings for United this season, who haven't been able to replicate his stunning form. And thirdly, United can rely more on their younger defenders, which is good news for everybody except Rio Ferdinand. Oh, and fourthly, it turns out that Nemanja Vidic is not, in fact, immune to physical pain, but that Phil Jones is.
Arsenal, however, didn't learn too much. Perhaps 'try not to play players who are ill?' but then Mathieu Flamini was far from the worst player in the team. All the possible conclusions that can be drawn from their defeat aren't easily rectified, other than by means of January purchases - in which case Arsenal desperately need another viable option at centre-back, and also an alternative to Olivier Giroud, who is too frequently ineffective in big games.
But the real problems that let them down - the utter ineffectuality of Mesut Ozil and Santi Cazorla - are not so easily rectified. That's not an issue you can mull over with a glass of wine and find a way to solve. It's just a big worry that's going to keep a lot of people up very late, drinking wine or not. If the money is there to rectify some of these problems in January, then there's not too much cause for concern. But that could be a very big if indeed.