No one combines the personal and political more intensely than Gordon Brown. So this weekend he will be undergoing agonising torture.
There is the private individual pain of confronting the one thing he did not want to happen: he is the prime minister who could not get himself elected, and time is running out on his tenure in the job that was his single-minded goal for more than 20 years.
And there is the nail-biting frustration of knowing that this weekend his fate lies in the hands of political enemies and inferiors. For a control freak, accustomed to dictating outcomes, that is political purgatory. At the end of the haggling, whatever the outcome, there will be a lasting radical realignment of public affairs in Britain. Mr Brown went into politics to change things but, most certainly, not like this...
Sitting tight in No 10 may seem like clinging to office but he justifiably argues it is his constitutional duty. It is also the way he is made.
He is notorious for his dour doggedness, so it was only to be expected that he would play his post-election hand down to the last card. Having schemed, fought and suffered countless snubs and counterplots to win the job, this prime minister was never going to go gently.
His entire life has been marked by the gritty overcoming of setbacks. From the loss of an eye and a narrow escape from complete blindness in his teens, family tragedies, career difficulties and national crises, Gordon Brown has often seemed like a character in a Greek tragedy – whenever things were going well, fate dealt him a blow.
He will now be wondering whether he could have done more to rescue his premiership and his government. Asked on TV during the campaign if voters were turning their back on Labour or on him personally, he replied: "I'll have to take responsibility – and I will take full responsibility."
In the embarrassing Piers Morgan interview, he freely admitted: "I accept I have to do better in the presentation area. I've got my strengths and I've got my weaknesses" – a line he repeated in his "mea culpa" email to party members after the Gillian Duffy incident.
Labour's campaign strategy betrayed its lack of faith in its leader. He was shielded until the final week, when suddenly the real Brown was unleashed – the thundering, old-time preacher whose storming performances were the highlight of party conferences.
The Citizens UK conference, two days before the election, was repeatedly brought to its feet, especially when he declared: "As you fight for fairness, you will always find in me a friend, a partner and a brother." Although Mr Brown was never going to to get the people to love him, they were warming to him – but his passionate appeal to "come home to Labour" was too late.
Making the moment even more sour for him is his conviction that he is the best man to secure the "stable, strong and principled government" he evoked in Friday's Downing Street statement.
When his walk-over result was declared in our home town, Kirkcaldy, Mr Brown seemed to be accepting defeat: his speech sounded like an obituary, listing achievements such as "the minimum wage, the child tax credit, the NHS renewed, more police officers, half a million children out of poverty, two million more jobs than in 1997..."
There was a farewell tone when he spoke of serving the people with whom he had grown up: "I'm proudest of all to have been returned as MP – now seven elections in a row – by the people who know me best, know who I am, what I stand for."
It was in Kirkcaldy that his deep antipathy to the Tories was formed. In his first days as Chancellor in No 11, he said to me: "We both remember the linoleum factories running down, then the miners being thrown on the scrapheap and later the job losses at Rosyth dockyard. In the Eighties, I made my first speech in Parliament saying we had to do something about the huge devastation of unemployment. Now, I can do something."
How will Mr Brown cope if he loses the ability to "do something" at the highest level? Initially, he will take it hard. With a doctorate in history, he does not want posterity to write him down as a failed footnote; he desperately wants a little longer, even in a salvaged coalition with the Lib Dems, to stabilise the state of Britain and bring about radical constitutional reforms.
Even if he is not given that chance, he should not be too despondent. His long-time colleague Henry McLeish, who was forced to resign as Scotland's first minister, speaks from experience: "It may be difficult, especially for someone as driven as Gordon, but he has to see it's not a disaster. He can take credit for doing a great deal of good and he has been a towering figure.
"In time, he may look back and think he didn't do too badly, certainly much more than most who go into politics. And he'll discover it's amazing when you leave office how much more rounded you become."
It is unlikely the PM will be allowed to hang around too long. When Lord Mandelson hinted that Mr Brown might be willing to stand down "at some point", it was not said lightly. Other ministers have suggested he might quit within two years, once the economy has recovered and an agreement on electoral reform has been completed – but that would be only in the unlikely event of a Labour-Lib Dem coalition lasting that long.
More likely is that Labour will find itself in opposition, in which case he would resign and start the scramble for a new party leader before the next general election.
And then what? In recent weeks, expecting the worst, the 59-year-old has said several times that he would "go off and do something else", especially charity work with his wife, Sarah: "I don't want to do business or anything, I just want to do something good, something that helps other people."
Sarah is patron of five charities, and president of PiggyBankKids, which she founded after her 10-day-old daughter, Jennifer, died in 2002.
Mr Brown has indicated that their work could be extended to the developing world and they could become ambassadors for children and the underprivileged. However, a former special adviser at No 10 believes he will not be allowed to step down as a statesman and, with supporters such as Kofi Annan and Barack Obama, he is likely to be offered a post at the UN, the World Bank or IMF.
Whatever the future holds for him, the most important consideration for Mr Brown will be his sons, John, six, and Fraser, three, who has cystic fibrosis. His private and highly personal life can only get better. But for the political Gordon Brown, there will always be that nagging regret...
5 things we'll miss: He's PR-proof and not posh
He's not privileged As he himself always says, he is a son of a hard-working Presbyterian minister from an ordinary, working-class town.
He's a hard worker He is never happier than when working on mind-numbing policy details – with no pesky humans to bother him.
He's almost PR-proof Despite Sarah's efforts to inject her husband with PR savvy, he remains irredeemably awkward in front of a camera.
He really believes in social justice and fairness It has driven his political ambitions over the past 30 years, except for the bit with the 10p tax. Oh, and the Iraq war.
His Javier Bardem vibe Though less than entirely photogenic and with an awkward laugh, his physical and social flaws make him seem odd but vulnerable.