WAS once briefly a football manager.

Stepped into a Sunday league gig after the incumbent had succumbed to a slight strain or, as the doc called it, acute cirrhosis of the liver.

It did not last long. The managerial career, that is. In terms of tactics, I borrowed heavily from the Kama Sutra Guide to Positions. This produced an unusual formation and a gaudy run of defeats. It was also responsible, though, for a spectacular end of season party.

But, like every self-harming football fan, I know a manager's job is as easy as taking some lemons and some peas and squeezing them.

We all chortle when somebody wails: "Who would be a football manager?" The massed chorus to this absurd inquiry is: "All of us. I mean you might not understand why Clarty Jimmy, who is in charge of sewage waste at the Hospital for Exotic and Contagious Diseases, might not want to hang up his rubber gloves for a million-pound career that is so full of chancers it could be called a bank. But, trust me, he might just be persuaded."

They say managers, too, face constant criticism. This was not evident when Arsene Wenger celebrated his 3000th day of not winning something with Arsenal. This is an heroic achievement. One would have thought that Wenger could have followed Portsmouth and Wigan Athletic in lifting an FA Cup trophy since his last triumph in 2004 when the ball had soddin' laces.

Or how about the League Cup? Since Arsenal last won it Aston Villa (twice), Leicester City (twice), Tottenham Hotspur, Blackburn Rovers, Middlesbrough and Swansea City have been among the teams to have lifted the trophy.

Aye, but Arsene just picks weak teams for the competition, say his supporters. There is the counter argument that Arsene picks weak teams for every competition but he picked his best for a meeting with Birmingham in the cup final of 2011. Arsenal went on to lose the final. Birmingham won it and went on to be relegated.

Yet he is called The Professor. This deserves the adding of Nutty. And nutty as in as nutty as the septic tank at the squirrels' commune.

Of course, Arsene is just the most conspicuous example of how managers are evaluated kindly if they talk about "playing the game in the proper way", know that a preposition is not a surgical implement and believe training is more than just playing five-a-sides before heading for a very happy meal.

Yet they are accorded some sort of infallibility when they are around for long enough. "Be careful what you wish for" is the standard response to any Arsenal fan who considers that his season ticket fee of a hundred squillion gazillion per game may not be the best investment he has made and maybe a change of leadership should be considered. This advice is offered, of course, by people like me who don't buy season tickets and are more likely to bump into a leading manager than an ordinary punter.

The most spectacular thing about managers is the obvious mistakes they make. Yup, David Moyes knows more about football than me but most punters know that Marouane Fellaini is a Manchester United player in the same way that I am a viable stand-in for David Beckham in an underwear ad.

Yes, Manuel Pellegrini is a drawer of the fine lines of football while I am the hyperactive wean in the crèche with the paintpot and so many E numbers I could supply a vowel for the next five series of Countdown. But I know Martin Demichelis is as reliable as a 20-year-old Lada that has been a veteran of the school run in the Khyber Pass. Pellegrini thinks that Demichelis is a mobile central defender. I believe he is as mobile as Central Station.

Every fan is aware of this myopia in their manager. I have watched football in seven different decades - from the fifties to the teens - and have been amazed they cannot on occasion see what the rest of us can.

Like when Arsene spends all summer looking for a top-class attacker and then signs another midfielder in Mesut Oezil for £40m. The German is then posted missing in big games and the strikers just miss. It is akin to giving your IT manager £40m for a new system and him coming back with an apology over the lack of an email service but pointing out that every bathroom in the building now has a Jacuzzi.

Most managers face a defining moment that shows them as horribly fallible. Arsene has now jumped the shark. It is a position but not as much fun as those in the Kama Sutra. Or so I am told.