This talent for self-deprecation, mocking himself and his work, has been missing in the torrent of words - most of them abusive - flung at Tim Bell these past 20 years. Not surprising that this element in his nature has been hidden: he hasn't given a newspaper interview for 25 years. So we only presume he's a total baddie, the cunning manipulator behind Margaret Thatcher, the conduit for captains of industry, the mouthpiece for foreign leaders as he tries to persuade us that deep down they are lovely human beings.
The latest rubbishing began when his firm was paid pounds 62,500 to advise the Government on next month's anniversary. It all turned - no, not nasty, funny really, when Dame Vera Lynn rose up against the idea of Spam fritter contests.
We sat down in his office, surrounded by framed newspapers. Actors have theatre bills. Footballers have medals. A bit harder for PRs to garner concrete proof of their existence, but he had managed a goodly number of headlines representing a triumph for his hidden art.
'I'll take my jacket off, if you don't mind, even though it will show how fat I am. You'll find me extremely unprecious. I don't take myself too seriously. Some people think that could be a fault. Of course there are days I do feel quite self-important, but really I haven't felt self-important since, oh, I was in my teens. So go on, ask me anything.'
Are you really an Australian? (It rarely pays to ask a hard question, first off.)
'My mother was Australian, I was born in London. My father was Irish, served in the RAF, then became a rep for Crosse & Blackwell. One day in Manchester he saw this man with a hump. He went up to him and said, 'Can I touch your hump?' The man said, 'That's most unusual, people don't normally comment on my hump. Would you like a job?' He turned out to be a boss of Pan Am Airways - and he gave my father a job in South Africa.
'While he was in South Africa, he turned to radio broadcasting. Remember Uncle Mac, on our radio during the war? My Dad became Uncle Paddy in South Africa. When I went out recently, to advise President de Klerk on his election campaign, I found that people still remembered Uncle Paddy. In fact, they knew more about him than I did. He left my mother when I was about four years old, but that's another story . . .' He does tell them well, our Tim, no wonder Mrs T found him so entertaining.
Age 52, brought up in north London, educated at Queen Elizabeth's Grammar School, Barnet, good O- and A-levels, but decided against university. Seems strange, as his mother had remarried, to a solicitor, the sort of background where parents might insist on higher education.
'I didn't fancy university. They wore duffle coats, smoked pipes and liked trad jazz, whereas I wore Italian suits and liked modern jazz. I played the trumpet in a band, and did have hopes of becoming professional, but I just wanted to start work and earn some money.'
He began at ABC Television, on pounds 7 a week, then after two years moved into advertising, rising spectacularly through the ranks, becoming managing director and then chairman of Saatchi & Saatchi.
'I started on what was considered the down-market side, media buying, never on the creative side. Basically, I was a suit.' In his days as a Saatchi boss he was renowned for having his chauffeur drive him from the office in Charlotte Street to lunch at the Etoile - all of 200 yards away. True? 'Oh, absolutely true. I liked to use the car phone, and to be seen arriving with a chauffeur. As a kid, I always hoped I'd be the sort of person who could walk into restaurants and be well known.'
It was through Saatchi's work with the Conservative Party that he met Mrs Thatcher - then carried on working for her personally when he left advertising for PR. His company, Lowe Bell, is now the second biggest PR firm in the country, employing 160, and is worth pounds 20m. It is about to go public, which should make him personally about pounds 2m. This will be his second killing. He netted pounds 4m, pre- tax, when he sold his Saatchi shares. He has a splendid house in Belgravia and drives a Bentley.
'I'm not rich. I'm well off.' Do explain the difference. 'Rich people have more money than they can ever spend. Well-off people have enough to live well without borrowing.
'I'm a capitalist, always have been. The only problem until now is that I've had no capital. The Saatchi money went on the house and other things, some of them foolish, such as clothes.
'I wouldn't say I was obsessed by money. What has obsessed me is having a successful career.' Which you have, no question, so what's the secret?
'My only real strength is objectivity. I try not to bring my own opinions to bear on someone's problem. I'm a bridge between the maker of something and the market they want to reach. In advertising, you are using paid-for media. In public relations, you are looking for third-party endorsement. Advertising is controllable. PR isn't.
'One-third of the accounts are straightforward launches, offering opportunities. One-third is basically communication, keeping the name alive. Only the other third is what one might call people with problems.'
David Mellor had a problem and came to you - and ever since you have been mocked and criticised for advising him to have that photo opportunity with his family. 'He's a friend who asked for my advice. He couldn't use his Civil Service office, as it was a private affair. The tabloids had had a five-day extravaganza, in which things had been totally fabricated, pure invention, later admitted to be false. It was David's idea to have the family photo, to disprove something which had been said. I said it would look phoney, don't do it. But he decided he wanted it - and I agreed to help organise it.'
What about Sir Ian MacGregor, chairman of the Coal Board? Your firm is supposed to have got a nice fee for advising him to wear a light suit on television so his dandruff wouldn't show. 'Perfectly true, but of course we did a lot more, which was never known.' Well done. But surely now and again you make mistakes.
'Loads of times. I remember Colin Moynihan asking me about the Pamella Bordes story. I told him not to worry, it was only a one-day wonder. I got that completely wrong.'
It's also been said you worked to get Baroness Thatcher her consultancy with a tobacco company. 'I don't work for her. She is just a friend. Anyway, I think you'll find the story is untrue.'
OK, so untrue or unfair stories about you keep on being repeated. If you are so good at PR, why can't you handle your own better? 'Because sections of the press tell fibs.' Haven't you told the odd fib in your time? 'Yes, of course.' He paused. 'Let's say I've sometimes handled things badly, when I've been rung at 5.30pm, when a paper's going to bed, and been asked for a comment. I've also been economical with the truth, in the sense of not giving more information about a client than I need to.
'The thing is, being in PR, the press are out to get you, and they have become very malicious. They don't like the fact that I'm Sir Tim Bell, but I'm proud of my knighthood. It's a manifestation of Mrs Thatcher saying 'Well done.' Columnists like to attack PRs as trivialisers of modern life.'
Are you suggesting that PR is important? 'No. PR is not important to society, but it has a function in society. It doesn't make the world a better place, but it does serve a practical purpose. Advertising and public relations are bastions of free speech.
'I love journalism and journalists. The British press is still the best in the world. I've just had to be tough when they set out to get me, and not let it hurt, but it does hurt my family.'
He and his wife, Virginia, who is 16 years his junior, were married in 1988 and have two children, five-year-old Daisy and three-year-old Harry.
He was married before, but this marriage is not mentioned in Who's Who. Why not? 'I don't know.' Oh, come on. Must be a reason. 'I married my first wife when I was 23. After five years, we realised it hadn't worked out and we parted, but we remained friends. She died later of cancer. We had no children.'
Two years ago, he found he had cancer of the colon. 'I naturally blamed my life of self-indulgence, but I'm told it's genetic. I suddenly started getting the most awful stomach pains, lost a hell of a lot of weight, and then had internal bleeding. I won't go through all the tests and stuff. On one vital day, when I was supposed to eat nothing, I was invited to the banquet at Buckingham Palace for the Sultan of Brunei, one of my clients. I couldn't miss that. The doctors weren't very pleased.
'Anyway, I've had the operation and chemotherapy, and everything seems fine, though they say you need to live five years to count as clear.
'I was petrified at the time. When I lay in hospital recovering, I did plan to change my life. I haven't really. My biggest fear in life is still the same: boredom. But I do spend more time with my kids.'
Is Lady Thatcher still your heroine? 'Certainly. I have met some remarkable people in my life, but she was the greatest. She was in touch with the mood of the people more than any PM has ever been, and she freed the people from the burdens of the state.'
Right, the D-Day fiasco - sorry, account. You don't seem to have achieved much for your fee of pounds 62,500? 'Our price was very competitive. Others quoted three times as much.' But your ideas do sound a bit potty. 'What ideas?' Those I've read about.
'Oh God,' he sighed. 'Listen, the Spam fritters were suggested by the Royal Marines, not us. The idea of street parties was created by the Sun, not us. We were asked by the Government to interface with all the organisations involved and come up with ideas for 'commemorating and celebrating'. Note those words. Our title for the project was 'The Nation Gives Thanks'. I leave you to decide what that wording means.'
Have you been carrying the can for the Government? More sighs. 'The point of D-Day is that we are commemorating freedom from oppression, so I do think people should be free to commemorate as they feel best. People are also free to criticise me.'
Which they are, alas for poor Sir Tim. He is still a keen luncher, in all the best places, despite his operation, but in the past couple of weeks, boorish strangers have been heard to shout as he is led to his favourite table, 'How's D-Day?' Very annoying. For an amusing, unaffected sort of chap, only doing his best to do his job.
This is the last of the present series of Hunter Davies interviews. Angela Lambert takes over until his return in the autumn. His book 'Hunting People - 30 Years of Interviews with the Famous' is published by Mainstream, pounds 7.99.