Imagine popular rage, therefore, when it was discovered that he escaped aboard lifeboat No 1 with the women and children — and it was whispered that he and his wife had even bribed the crew not to rescue victims in the water, in case the boat should be swamped. As it was, this hateful calumny was later disproved; and Duff Gordon’s defenders made an important point about his basically wretched behaviour. It was true that he was one of a small percentage of men to survive, and it was true that lifeboat No 1 carried — incredibly — just 12 people, when later boats were full to bursting of terrified human beings. But the reason his lifeboat was so comparatively empty was that when it was launched, so many people on board Titanic still shared the optimism of the Costa Concordia waiters.

They believed the newspaper claims that Titanic was unsinkable, and you can see their point. It must have seemed utterly incredible that a gigantic steel vessel, in a flat calm, on a well-known route, could come a cropper on a piece of frozen water. And to the cruise ship waiters this weekend, it must have seemed even more incredible that their floating village — twice as populous as Titanic — could just flop on its side within sight of Tuscany.

Millions of people take these cruises every year, including 1.7 million Britons, and the boats are one of the safest means of transport on earth; and as they felt that first crunch and tremor in the hull, it is no surprise that they defied the evidence of their senses and continued to scoop up the olives and the breadsticks as they rained off the tables. They were in the grip of denial, a denial based on the fallacious and complacent inductive logic that because things have been all right so far, they are going to continue to be all right — and as with the good ship Concordia, so with the ship of state.

It is now more than 300 years since that saucy and magnificent vessel, HMS Great Britain, has sailed the seven seas, and for those of us who have been aboard all our lives, it still seems out of the question that she could really hit the rocks and break up. Britain is a giant fact, one of the world’s most successful political unions, that has produced everything from an empire to a broadcasting corporation to a particularly nasty type of sherry. I am like the Concordia waiters, in that I can’t really believe, somehow, that we can be set on a course for destruction.

But look at the facts, my friends. Look at that submerged reef marked “devo max”, or fiscal independence for Scotland. If you can unpick the fiscal union, what is there to maintain the monetary union? And if you unpick monetary union — as George Osborne rightly points out — then political union is dead. The Coalition Government is like the chap in the crow’s nest of the Titanic (his name was Frederick Fleet) who strained his eyes into the night at 11.40pm and then cried, in a stammering howl: “Iceberg, right ahead!” I don’t know if there is time to avoid a rupture.

As things stand, the polls suggest the people of Scotland are too wise to go for full independence; and, as I say, no one currently believes in their bones that it will really happen. But then, the waiters of the Costa Concordia couldn’t understand how their colossal ship — the biggest ever built in Italy — could founder in such humiliating circumstances, and the unsinkable Titanic lies broken in two at the bottom of the sea. That is the nature of slo-mo disasters: they can change very quickly, from being an outlandish theoretical possibility to a predestined inevitability.

Imagine popular rage, therefore, when it was discovered that he escaped aboard lifeboat No 1 with the women and children — and it was whispered that he and his wife had even bribed the crew not to rescue victims in the water, in case the boat should be swamped. As it was, this hateful calumny was later disproved; and Duff Gordon’s defenders made an important point about his basically wretched behaviour. It was true that he was one of a small percentage of men to survive, and it was true that lifeboat No 1 carried — incredibly — just 12 people, when later boats were full to bursting of terrified human beings. But the reason his lifeboat was so comparatively empty was that when it was launched, so many people on board Titanic still shared the optimism of the Costa Concordia waiters.

They believed the newspaper claims that Titanic was unsinkable, and you can see their point. It must have seemed utterly incredible that a gigantic steel vessel, in a flat calm, on a well-known route, could come a cropper on a piece of frozen water. And to the cruise ship waiters this weekend, it must have seemed even more incredible that their floating village — twice as populous as Titanic — could just flop on its side within sight of Tuscany.

Millions of people take these cruises every year, including 1.7 million Britons, and the boats are one of the safest means of transport on earth; and as they felt that first crunch and tremor in the hull, it is no surprise that they defied the evidence of their senses and continued to scoop up the olives and the breadsticks as they rained off the tables. They were in the grip of denial, a denial based on the fallacious and complacent inductive logic that because things have been all right so far, they are going to continue to be all right — and as with the good ship Concordia, so with the ship of state.

It is now more than 300 years since that saucy and magnificent vessel, HMS Great Britain, has sailed the seven seas, and for those of us who have been aboard all our lives, it still seems out of the question that she could really hit the rocks and break up. Britain is a giant fact, one of the world’s most successful political unions, that has produced everything from an empire to a broadcasting corporation to a particularly nasty type of sherry. I am like the Concordia waiters, in that I can’t really believe, somehow, that we can be set on a course for destruction.

But look at the facts, my friends. Look at that submerged reef marked “devo max”, or fiscal independence for Scotland. If you can unpick the fiscal union, what is there to maintain the monetary union? And if you unpick monetary union — as George Osborne rightly points out — then political union is dead. The Coalition Government is like the chap in the crow’s nest of the Titanic (his name was Frederick Fleet) who strained his eyes into the night at 11.40pm and then cried, in a stammering howl: “Iceberg, right ahead!” I don’t know if there is time to avoid a rupture.

As things stand, the polls suggest the people of Scotland are too wise to go for full independence; and, as I say, no one currently believes in their bones that it will really happen. But then, the waiters of the Costa Concordia couldn’t understand how their colossal ship — the biggest ever built in Italy — could founder in such humiliating circumstances, and the unsinkable Titanic lies broken in two at the bottom of the sea. That is the nature of slo-mo disasters: they can change very quickly, from being an outlandish theoretical possibility to a predestined inevitability.

But if the film takes liberties, it is poetically truthful. It is true to the essence of Thatcher, and above all Meryl Streep is amazing. She enters into her; she becomes her: the ruby lips, the flashing eyes, the pineapple hair, the pale skin transpiring at every pore with the fire of pure certainty. Somehow this God-gifted, 62-year-old American actress has re-explained to the world what it was like to see, meet and be the West’s first female prime minister.

Somewhere the film’s director has said that it is a King Lear story, an examination of a tragic loss of power, a meditation on the sorrow of old age. That may have been the intention of the writer and director (neither of whom, I guess, would call themselves ardent Thatcherites) - and yet it is the younger, stronger Thatcher/Streep who seizes the film and takes it over. I watched the matinee in Putney, and most of us agreed afterwards that the dementia stuff was actually quite tastefully done - a sensitive treatment of an important reality for millions of families. We just felt that there was too much of it.

Yes, she is eventually felled by the men in grey suits, but by the end Streep has effectively reminded us of what Thatcher was really all about. It wasn’t just me-first, get-rich-quick, Devil-take-the-hindmost exaltation of the values of Essex Man. That was the caricature. Thatcher herself emerges from this film as a far more revolutionary and inspiring figure - because she was a woman. From the very beginning and at all the critical moments you can see that what really actuated Thatcher was a feminine impatience with the cosy, clubby, complacent politics of the post-war consensus - a consensus that was held overwhelmingly between men of a certain age and class. Of course she believed in thrift and hard work and rewards for merit - but a proper understanding of what Thatcher really stood for is vital today.

To take the issue of the hour, I believe she would have strongly disapproved of boardroom greed. She never really much liked the City - she thought that on the whole the bankers liked interest rates to be too high for the good of her vision of a property-owning democracy. Insider traders were prosecuted on her watch, after years in which such tip-offs had been treated as a “victimless crime” that was traditionally conducted over a vinous, nose-tapping lunch. She got rid of automatic commissions for stockbrokers.

She believed in competition, and allowing the market to work - not stitch-ups. Ask yourself what Margaret Thatcher would have thought of a system where directors sit on each other’s “remcoms” - remuneration committees - and defend each other’s expanding awards, even when the directors in question have presided over commercial disaster of one kind or another. She would have thought it was absurd. Thatcher wasn’t against money, and she wasn’t against pay as an incentive to real exertion and real talent. But - and I have taken the trouble to consult her biographer, Charles Moore, who supports the point - she would have been totally opposed to all that now whiffs of a male-dominated cartel, a you-scratch-my-back-and-I’ll-scratch-yours conspiracy against the shareholders and the wider interests of the company.

Thatcher was brought up a Methodist, with a deep attachment to the values of the Protestant work ethic. She would have been against any kind of crony capitalism, and as for the solution - well, she would not have wanted pay set by politicians, and she would not have gone for any kind of continental-style socialism. But I reckon she would certainly have gone for any kind of poujadiste revolt that gave shareholders a simple way of voting down pay awards they thought were excessive.

In tackling boardroom greed, David Cameron is not bucking the market. He is acting in the true Thatcherite tradition of the Conservative Party, because male clubbiness, jobbery, idleness and complacency were the very things Margaret Thatcher fought against all her political career.

Now a psychiatrist might look at these symptoms and conclude that the British are somehow needy. We seem to want some kind of comfort. We are evidently anxious. After all, you drink when you need to drown your sorrows or in some other way deal with reality. You compulsively buy stuff when you want to make yourself feel better. And the classic analysis suggests that you eat more than you need when you are unhappy about something.

So what is up with us? I suppose it might be some kind of Weltschmerz, a general disappointment that Britain is no longer incontestably the most powerful country on Earth. Some people might even argue that our overeating is all caused by the gloom of the media. Perhaps it is the travails of the euro that is sending us to the fridge, or doubts about the durability of the Arab Spring. Perhaps it is the BBC economics guru Robert Peston who is causing us to motor through the custard creams. It’s possible, but somehow I don’t think that is how people really behave. They don’t eat or drink or overspend in response to external political events.

It’s much more likely to be all about us and how we feel about ourselves. We live in a media-saturated age where we are constantly told that we would attract greater admiration from other human beings if we looked better or owned a smarter car or a newer pair of gym shoes. People feel challenged to possess this or that useless item, and we judge ourselves harshly when we fail. The consumerist boom has been accompanied by a widening gap between rich and poor, and it follows that there will be more disappointment out there – more unhappiness, more jealousy and more self-punitive overeating.

Food gives us that fix of calorific comfort that we need, and of course we are sometimes so horrified by the results of our overeating that we have to console ourselves with some small pleasure, and so we eat even more. We need to end this mad cycle, and the first and most important step is to end the national cult of self-dissatisfaction, our envy of others when we have material things our grandparents could only dream of.

Some might say that we need to cure our unhappiness and associated overeating by massive redistribution of wealth. Well, they tried that in places like Russia and Cambodia and it wasn’t a roaring success. They had Marxist-materialist societies in which elites hoarded wealth and privilege in a way that was all the more disgusting for being done in the name of the people. Others might urge a more ruthless programme of NHS-funded stomach stapling. Apart from the expense, it does seem a curious denial of personal responsibility.

Surely what we need, if we are all going to lose weight, is to create a less insecure, hung-up, envious and self-hating kind of society. Easier said than done, I grant you – but that is the root of the problem. If you have the time before going back to work, I recommend a film called Dodgeball. Here we see a world of two gymnasiums – Average Joe’s and Globogym. We celebrate the triumph of physical mediocrity over the hysterical body fascism of White Goodman, played by Ben Stiller, who makes his money by persuading people they are the wrong shape.

That is what is required: a Britain where we are so happy in our skins that we don’t stuff our faces. Somewhere along the line we managed to lose religion without finding any alternative source of spiritual nourishment. Hence the use of food, drink and consumerism. Some day a prophet will arise – perhaps in these pages – who will teach us a new form of self-control and moral wisdom. But until that glad day I leave you with my patent diet. Lay off cheese. Avoid alcohol. Cut out potatoes, bread, pasta and stuff like that. Eat stupendous quantities of kale and apples and perhaps the odd small piece of dried fish. It’s a piece of cake – which is what you will certainly deserve if you keep it up for more than four weeks. Happy New Year!