Into every life there comes a day, or perhaps a few of them that can be easily joined up, that may very well define the rest of your existence – a time which you can seize or let go. Yes, of course, we are talking about Arsenal Football Club.
In this matter of fulfilling potential, of grasping that sometimes there are opportunities which might never appear again in quite such a cluster, there is arguably no more fascinating case study than Arsène Wenger's team.
Tonight at the Nou Camp they have to survive the firestorm of brilliance that only Barcelona can produce at their best. There may indeed be moments when their entire lives pass before their eyes.
In a few days' time they face a wounded Manchester United in the FA Cup and between now and the end of the season they have their best chance in six years to prove that they can win the Premier League they once engulfed in a superb, unbeaten season.
Truly, it is a dazzling prospect for the likes of Wenger's most gifted lieutenants, Cesc Fabregas, Samir Nasri and Jack Wilshere. But then it is also a trapdoor already half open to the most devastating consequences. For if it is true, as some are now persuasively arguing, that this is a title race stripped of the certainties you can reasonably attribute to champions-elect, if the winners must face the charge that their prize came by default, the cost of failure in such a year will surely haunt no one more deeply than Arsenal.
They are, after all, the team that those still capable of rising above the great kraal of English football tribalism most want to succeed.
Not just for themselves, for the vindication of a belief that football is nothing if it is not redolent with skill and beauty, but because their whole operation remains in these days of crazed economics and randomly imposed wealth, a conspicuously intelligent attempt to bring logic to the madhouse.
Who, by way of contrast, would make champions worthier of the approval of an objective soul?
Manchester United? It would be another tribute to the competitive instincts of the manager and the players, and no one could complain if in the middle of their current misery they find some spark of the old defiance, but, no, in a non-vintage year the height of their achievement has been no more thrilling than a papering over of the cracks.
Chelsea? Distaste for the way the club is run can only be compounded by the admission of their manager, Carlo Ancelotti, that he has no sense that the men out on the field are his team, and that he is merely there to supervise and make the best of the material he is given. None of the great managers of English football, including Wenger, would have accepted such a limitation on their work.
Manchester City? The sense of a team, rather than an accumulation of expensive players, remains elusive. They may well be something some time but for the present they seem most at war with a basic concept of how you build a team.
Spurs? Perhaps next year. We might say the same of the new Liverpool.
Meanwhile, there is a title, a Champions League and an FA Cup to fight for and if Arsenal are excited by the possibilities they must also confront some of their worst demons. They must, privately at least, wonder if there still lurks in the team psyche a competitive weakness that emerged around the time Patrick Vieira and Thierry Henry declined and disappeared.
Fabregas, at the age of 23, has produced a superb body of work. Nasri has shown world-class quality and if ever there was a sure-fire entrant to the highest echelon of the game, it is surely Wilshere. Yet at what point do such major talents – which, of course, also include Andrei Arshavin and the injured Robin van Persie and Theo Walcott – coalesce in that certainty which separates the champions from the merely good?
Yes, of course, there have been glimpses. The defeat of Chelsea earlier this season certainly suggested itself as a moment of breakthrough and, who knows, the recent recovery against Barcelona at the Emirates may still burn brightly enough in Barcelona tonight. But you have to say such things on a wing and a prayer.
For all the virtuosity, it is too often a broken wing. The defeat against Birmingham City in the League Cup final will shrivel to nothing if Arsenal can put something silver in their cupboard this spring, but for the moment it surely represents the reopening of an old question: do they believe enough in their own talent? As recently as last Saturday, in the middle of United's current implosion, it had to be asked again in the home draw with Sunderland. Wenger boiled at the mistakes of officials – but how much of that rage would have been properly directed at the failure of his team?
Arsenal's last collision with United left too much room for sombre reflection. Once again, the League leaders were much less than imperious, but Arsenal's response was tame indeed. Nasri, on whom so much expectation had settled, was virtually anonymous.
It means that whatever mood Wenger carries into the Nou Camp tonight there will be an inevitable ache. It is one that comes when you fear that you have waited too long for a crowning moment, a confirmation of all your best hopes. Certainly, he is not likely to be too soothed by the declaration of the poet that into every life a little rain must fall.
Wenger can fairly claim to have already sloshed through more than a few seasons of monsoon – enough, anyway, to warrant the emotional support of every fair-minded football fan. Arsenal have, after all, had their share of rain – they deserve that it should not now come down heavily impregnated with acid.
To err is human – but another pair of eyes would have helped out Dowd
Graham Poll faced up to his most anguished moment in a distinguished refereeing career – when he handed a Croat player his third yellow card in a World Cup game six years ago – with such honest regret that his self-elected role as a leading commentator on match-officiating is challenged only by those who do not accept that to err, whoever you are or however accomplished, is human.
This being so, his assessment of Phil Dowd's performance at Anfield on Sunday, carried more than usual fascination.
Though he agreed that Jamie Carragher should have received a red card for his tackle on Nani (above), he closed ranks to the extent that, in his opinion, the degree of the offence was not so apparent in real time as on TV reruns. For those of us whose blood ran cold the moment Carragher launched himself at Nani, this is somewhat surprising.
However, it surely suggests yet again the value of having a fourth official with the ability to note the severity of offences and immediately inform the referee. This, unofficially, enabled the 2006 World Cup final referee to remove from his record the possibility that he might allow Zinedine Zidane to make any further contribution after head-butting an Italian defender. It would also have prevented Thierry Henry's cheating in a qualifying match against the Republic of Ireland and allowed Frank Lampard's perfectly legal goal against Germany to count in another important World Cup match.
In his "Official Line" column in the Daily Mail, Poll added the opinion that Dowd might also have sent off Liverpool's Maxi Rodriguez for a thigh-high tackle on United's Rafael, along with Luis Suarez (for pulling the United player's hair) while handing the victim of that provocation a yellow card for a high tackle on Lucas.
Poll concluded: "It was a pity Dowd missed those few incidents because otherwise he refereed well." How much better, though, would he have done with an all-seeing eye and a helpful word in his ear?