I've led a quiet, well-behaved, dull life. But on reflection, I shall not be putting myself forward for public office

It seems an appropriate and prudent moment to confess that I have been entirely faithful in my marriage. And I am not defining this sexual fidelity in any narrow, technical or legalistic sense. To use the slightly disturbing terminology of my children, no sexing and no snogging either.

This is important not just because of love, affection, friendship, commitment, vows taken, but because, to use another expression, my wife knows where all the bodies are buried. One of the "shaming details" in Margaret Cook's act of "naked revenge" against her ex-husband, demonstrating his drink problem and his lack of fitness for high office, is that she once found him flat out in the dining room with an empty bottle of brandy by his side. Only once? And in his own dining room? And that's considered a drink problem?

Reading the list of our Foreign Secretary's foibles, shortcomings, betrayals, indiscretions (if moaning to your wife about your colleagues counts as an indiscretion), a part of me was thinking variously "how pathetic/squalid/not too bad really", while another part of my brain was working overtime through various episodes in my life when things got out of hand due to emotion or intoxication. And then I tried to make calculations. Who was actually present? Are they likely to remember or were they even more drunk? Who might have been told? Are there any photographs or anything written down?

On balance, I consider myself to be a person who has led a basically dull, well-behaved, quiet life, but nevertheless, on consideration, I shall not be putting myself forward for public office.

Is Robin Cook's sexual infidelity unusual? I've just read Peter Biskind's horribly fascinating book about Hollywood in the seventies, Easy Riders, Raging Bulls (published by Bloomsbury). What is shocking is not the behaviour of the people you knew were a bit wild, like Dennis Hopper and Jack Nicholson. It's the behaviour of the people you thought were decent and sensitive. I had thought of Francis Coppola as a regular family man - he has certainly employed almost every member of his extended family. So it was a little dismaying to read the following bizarre sentence about the shooting of Apocalypse Now (Ellie is Coppola's wife): "Francis had been carrying on various affairs with the women on the set, complaining that he wanted to have more children, but Ellie refused." I think by "have", Coppola meant "father", but in Hollywood you can never be sure.

Even if you have no interest in film, the book is fascinating and disturbing for what it suggests about the male psyche. A group of young men, who had mostly been nerdish loners in their teens, arrived in Hollywood and quickly became very famous and very rich. Suddenly they could do anything they wanted, and it seems that most of them did, whatever the cost to their children, wives or, in the slightly longer run, to their talent and careers. If a being from another planet who had conducted a study of human behaviour was asked why Hollywood men behave so badly, he or she would probably reply: "Because they can". There isn't even much stigma attached to sexual or chemical excess, so long as your films make money. Politicians have more of a problem. They have the opportunity but they're meant to keep their behaviour secret.

The change in the attitude to secrecy has been very sudden. Paul Theroux has apparently been defending himself against criticisms of his "warts-and-nothing-but" portrait of V S Naipaul by quoting the hostile reception that greeted Boswell's Life of Johnson for revealing embarrassing details about its subject's behaviour. But Johnson had known Boswell was planning to write his life and, above all, he was dead and no longer around to be humiliated.

Both Cook's and Theroux's books, as well as much modern journalism, depend on violating the distinction between private and public life. The point of this separation is not that some of us have secrets but that we all have peculiarities when we are at home with the blinds drawn. Consider how oddly embarrassing it is if someone has been observing you while you thought you were alone, even if you weren't downloading child porn from the net. Poking that interesting stuff out of the corners of your eyes is bad enough.

We already knew that Robin Cook was an adulterer. For the rest of it, he did the sort of stuff that people do when they are supposedly not on display. There used to be the old saying that no man is a hero to his valet. Now that the valet will sooner or later sell his story to the Murdoch press, the saying will have to be altered: no man is a hero.