On Wednesday night I literally lost the plot. The experience led me to some surprising thoughts about politics and journalism.

Of Wednesday it might be more honest to say I never got the plot properly in the first place, but what I got was lost within minutes. We were watching Verdi's opera Simon Boccanegra at the Royal Opera.

Don't ask me to tell the story because if synopsis defeated the programme notes it will certainly defeat me. All I gathered was that a string of ghastly misunderstandings and fiendish cover-ups led to key figures not knowing that a beautiful woman with a fabulous voice was one person's daughter rather than somebody else's; and her actual father did not know. The rest, which concerned Italian city-states, conflicts, uprisings, abductions and deadly conspiracies, revolved around this mistaken identity.

All was revealed at last, of course. The revelation occurred just in time, and... Enough. I'm losing your attention. This narrative lost mine so instead I sat back and let the bright colours and lush sounds sweep over me.

And I fell into a sort of one-man internal symposium on the Role Of The Plot In Fiction. People with degrees in literature may already be familiar with the thought that occurred, and I am perhaps reinventing the wheel, but it was this: that in drama and the classical novel two of the commonest and most reliable mainsprings to the narrative - and they are linked - are (1) concealment and (2) misunderstanding. The climax, denouement or moment of truth comes when all is revealed. This occurs near the end. When it comes too late the work is called a tragedy. When the implications are hilarious it is called a farce. When two lovers head off together into the sunset it is called a romance.

In Othello Iago fabricates a tale of adultery so the hero murders his wife, and all is revealed too late. In Oliver Twist the young orphan is unaware of the circumstances of his birth or his inheritance, but gets it in the end. Middlemarch is full of unsuspected duplicity and the undisclosed contents of wills. In Pride and Prejudice it is Darcy's secret generosity that, when discovered, brings Elizabeth into his arms. In the key scene in Gone with the Wind, Scarlett confronts Ashley in the library and discovers he's engaged to marry his cousin. She slaps his face, he exits, she throws a vase, and startles Rhett from the sofa where he had been concealed, overhearing all. And as for Sheridan, Congreve or Feydeau, and those cupboards, ears to doors, stolen letters, telltale handkerchiefs and people under beds...

...Well, you get my gist. Not that all fiction is like this. Serious modern literature, as opposed to popular fiction, sometimes tries to forgo plot completely - with mixed results. Nor should we think that the greatness of a great work of fiction resides in the narrative string on which the pearls of fine writing or human observation are strung. But, like plumbing, the plot is crucial even if it is not the main event. It is highly significant that though the first meaning of the word “plot” may be “narrative”, the second is “a secret plan”. The regularity with which even the finest authors cling to an often silly storyline about surprises, secrets and lies suggests a deep human need in the minds and hearts of audiences for a story of concealment and a moment of discovery and final resolution.

To my mind there is a grave problem about this. We expect, of course, that fiction will idealise, abbreviate, simplify, even caricature, reality: it must, because reality is slow and untidy, while fiction can lay bare essential truths with speed and economy. But the device of the “moment of truth” teaches an essential untruth. It tells a big lie about the human condition and about history.

In politics, my focus as a writer, as in real life, I find there are very few moments of truth. Serious, persistent misunderstandings are quite uncommon. Little that is important is successfully hidden for long. Most people, mostly, for most of the time, have a pretty good idea of what is going on, or have at least suspected it all along. Few apparent heroes whip off masks to reveal themselves as villains, or vice-versa. The estimates we make of character and intention are built and (where necessary) revised gradually as evidence accumulates: not in a flash of revelation near the end of Act V.

But we who report or offer commentary keep trying to impose on reality the fiction writer's template of the moment of truth. Readers have been encouraged to expect it. So we invent “smoking guns”, “silver bullets”, “killer facts”. It is one of the reasons we love judicial inquiries with their accompanying sense of detective investigation, dock, witness box, final verdict and sentence. This does not so much simplify or caricature reality as turn it on its head.

The downfall of Gordon Brown, when it comes, will owe little to betrayal, treachery, conspiracy or surprise. These elements may be present; but as consequences, not causes, of the slow decline of a person - any person - who is not up to his job. Tony Blair and Alastair Campbell will not return, one day, to cheers or boos, but simply fade away. The latter's unexpurgated diaries, when published, will only confirm - with quotes and examples - what most people thought from the start.

The “honours scandal”, the Abrahams affair, Lord Levy-gate and all that, only illustrated what anyone who follows politics knows has been a truth about the honours system in Britain for more than a century. One day we'll know for sure that elements in Washington and Downing Street sexed up, played up and occasionally made up the War on Terror for a mixed bag of motives - some good, some bad - but the trouble is, we know that already, don't we?

Whenever a Tory government finally does slam the brakes on public spending, we in the media and politics will confect a splendid sense of “Aha!” about it all - but who really doubts, even today, that this must come?

There do exist storylines in modern British politics but they do not involve rabbits, hats, smoke, masks, daggers or ticking time-bombs. The storylines are limper, drabber, slower and more obvious. Individuals seek prominent positions for themselves, the public hopes to have its cake and eat it, everyone wants to pay themselves more money, greedy interest groups squabble over a finite pot... and, beyond that, Lenin's “who - whom?” (“who's screwing whom here?”) just about sums it up.

Tell me I'm wrong. Tell me Wendy Alexander and Peter Mandelson are in fact the bastard children (birth certificates doctored by Lord Goldsmith) of a secret liaison between the late Donald Dewar and Margaret Beckett, under orders from Tony Blair in Washington to insinuate themselves into Gordon Brown's circle then detonate it from within.

“Mother!” “Brother!” “Son!” “Treachery!” Bang. Aha. Curtain. And leave Verdi to compose the final chord.

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