Simon Kelner: A rare view of the patron saint of modern Brit art

As a founding father of modern advertising, Charles Saatchi clearly knows a thing or two about image. He understands how to influence public perception, and how to get a message across powerfully and effectively.

He's allowed an image of himself to be constructed – the reclusive, truculent, punctilious contemporary art collector who moves the market like no other – and has played along with it for all its worth. Don't you just love someone who throws a fabulous party and doesn't turn up to it? Someone who is in public life, but rarely turns up in public? And who exists in a world where publicity is key, yet shuns all forms of publicity himself? You may know that he has a domestic goddess for a wife, and that he is the patron saint of every modern British artist.

But, because he cleverly chooses not to do interviews, he has – unlike many other significant contemporary figures – been able to keep to himself his feelings on such important matters as, say, The Apprentice, or, indeed, the legalisation of gay marriage. (We look instead to Archbishop Sentamu's weekly column in The Sun, sent every Sabbath by God straight to Wapping, for such enlightenment.) This means that when Mr Saatchi does hold forth on what interests him, it is something of a news story in its own right. What a brilliant piece of marketing!

So this intensely private man has just brought out a book in which he answers questions posed by journalists and members of the public. In the style of a Damien Hirst painting, its studiedly iconoclastic title is Be The Worst You Can Be: Life's Too Long For Patience & Virtue, and it contains, among many other pearls, his views on getting older, the vulgarity of the art world, dieting, being married to Nigella, and the Sugababes.

It makes fascinating and entertaining reading, and Saatchi is an original thinker whose opinions have a freshness that comes from his not being over-exposed. He has a fondness for the witty epithet – when asked about divorce, he said that "wives make excellent housekeepers. They always manage to keep the house" – and has an entertaining take on most subjects.

Do you have a party trick, was the question. Not attending, came the reply. He is honest and opinionated in a way that is very refreshing for someone with a public profile. One questioner asks him about his "lack of social conscience". "I may be a disappointing person in many ways," he responds, "but at least I have never fostered grand designs for social engineering." He says that local councillors, instead of polishing their green credentials, should concentrate on "having the lifts on the estates working, and not stinking of urine". Concentrate on little actions rather than grandstanding, he says.

He is particularly loquacious on what he calls the "hideousness of the contemporary art world", which, he says, has become "the sport of the Eurotrashy, Hedge-fundy, Hamptonites". He develops this theme: "Even a self-serving narcissistic show-off like me finds this new art world too toe-curling for comfort."

It's strong stuff, from someone who really knows. Perhaps he really is a show-off, in which case it's something of a shame that he doesn't show off a little more often.