It was a very emotional Gordon Brown we saw giving his first speech (watch it here) as prime minister standing outside Number 10. He was hesitant, he was nervy as he got out of the car, unsure where to stand even. We got used, over the years to Tony Blair, a man who loves the cameras. The media were shouting at Brown during the speech - they wanted the famous Number 10 in their shots. But that's not Gordon Brown's style.
He delivered his words with confidence, but his nervousness was very, very evident.
His message was an intriguing one: change. That was the signal he wanted to send. And a degree of humility as well, quoting his school motto at the end - that he would "Try my utmost."
He knew that his words would be dwelt on, repeated again and again, and that he'd be tested against them. When people see the ups and downs that any prime minister and any government has, they'll say, did he live up to what he promised. Which is why his choice of words was so intriguing. "I will try my utmost" - it's hard to be found failing or wanting against that.
And we wait to see what the signal of change will mean - not just on health, or education, affordable housing or even trust - but in terms of our sense of what it means to be British. My guess is that that will be one of the great surprises of this Brown administration.
Drama it turns out can both eerily predict reality and occasionally get things ever so slightly wrong.
Remember the Christmas special The Thick of It? When the Blair figure resigns, the Tory spin doctor is shown running round Central Office shouting "This is the line, right. For the next 24 hours you praise him, right? You praise him like he's your dead brother." Could David Cameron have been watching?
As for the kissing of hands, my latest info is that the movie of The Queen was right to show Tony Blair kneeling and kissing the Monarch's hand. However, this was not what happened today. Quite why this is the case I am still struggling to find out.
Extraordinary. Gob-smackingly spine-chillingly hair-raisingly extraordinary.
Tony Blair planned to say nothing as he left Downing Street for the last time, but his carefully laid plans were once again torn up by his wife. As Mrs Blair got into the Jaguar to leave Downing Street for the last time, she looked directly into the cameras just feet away from her and spoke - not whispered, not mouthed - the following: "Goodbye. I don't think we'll miss you" (watch for yourself here).
Now that's an end to suggestions that Tony Blair is leaving entirely at a time of his own choosing (though he did choose the day and wishing all well as he did so).
One more thing. Earlier when I bumped into Mrs Blair and three of her four children as they were waiting in Parliament's central lobby to be escorted to the public gallery to watch prime minister's questions, I said to one of her children: "I hope you enjoy the day." They smiled. She looked at me with daggers.
CLARIFICATION 1600 BST: When earlier I wrote that this was "an end to suggestions that Tony Blair is leaving entirely at a time of his own choosing", I seem to have provoked some consternation.
Let me explain what I meant. The attempted coup last autumn DID force Tony Blair to promise to leave office before he wanted although he was nevertheless able to choose the precise date on which he left. Cherie Blair is angry with Gordon Brown for those events and with the media for the way she perceives they attacked her and her husband.
There were quite extraordinary scenes at PMQs (watch for yourself here), but not in the way I'd expected.
The House of Commons goes 'hear, hear', remember, it doesn't clap. If it claps, it doesn't stand for an ovation. It did both of those things for Tony Blair.
On all sides, MPs of all colours got to their feet spontaneously and applauded him as he walked out of the chamber, ending a Question Time quite unlike the one I suspect he was prepared for, and quite unlike the one that his backbenchers desperately wanted to see. They wanted a Thatcher-style bashing of the opposition - but David Cameron (as I mentioned previously) gave an extremely clever Parliamentary performance, sucking all the political heat out of the occasion.
It was more of a sentimental farewell than a long-awaited political bashing.
Clever. Very clever. David Cameron knew that today he'd been set up to be the jester at PMQs. Thus he designed questions to make sure that all the political heat was sucked out of the chamber - praise for the armed forces followed by questions about the floods then the Middle East and then praise for the PM's achievements and best wishes for his family.
It worked. As Labour MPs muttered and heckled all Tony Blair could do was thank him whilst his wife Cherie mouthed "thank you" from the public gallery.
Yesterday I surprised some viewers of the Six O'Clock News by saying that if Cameron were relaxed about the defection of an MP I was a "pineapple". (My six year old son's favourite affectionate insult these days which just popped in to my mind).
Today's performance proved that Cameron is more cucumber than pineapple.
Just a few minutes ago, just behind me in the central lobby, Cherie Blair with her children. Here today to watch, from the public gallery, their father perform for the last time in PMQs.
There's great expectation, and a great buzz, in the corridors here. I bumped into one Labour MP who jokingly had removed the prayer card (that's the way you book your seat in the House of Commons) belonging to Dennis Skinner - who of course always sits right at the front - and put the new convert, Quentin Davies, in his place. Somehow I don't think Mr Skinner will allow that to go on.
The same MP was telling me that he'd just had a call from Downing Street in the last few hours, asking what he was going to ask Mr Blair, as his position on the order paper was low enough to raise concerns - it could, possibly, be the last question. This MP said to me, "if they think I'm going to ask him a nice question now, after 10 years, they can think again".
I've no doubt Mr Blair will feel nervous. Any great performer - and whether you love him or loathe him he is one of the truly great political performers - gets nervous before an occasion like this. He knows this is the moment he bows out. He knows the clips from this will be shown not just on tonight's news, but endlessly as part of the archive of the Blair years. He'll want to enjoy it, and to get it right. And, of course, he'll seek to embarrass David Cameron the day after he lost an MP. and Mr Cameron will have to do his best to look straight back, and to look calm, even when he isn't.
Whether their departure is planned or unplanned, prime ministers always find leaving office a shock. Not only will the prime minister instantly become plain old Mr Blair, there will also be other indignities. I have another of Michael Cockerell's great TV political documentaries to thank for the following tales.
• Harold Macmillan had a man from the Post Office round within two hours of resigning to rip out his taxpayer funded phone
• Ted Heath emerged from resigning at the palace to discover that he had no car. "His" car - in fact, of course, it was the prime minister's - was collecting Harold Wilson. A plaintive call had to be made to the government car pool for a car for Mr Heath. These days ex-PMs do get cars - largely for security reasons - but it won't be the one Mr Blair's used to
• Margaret Thatcher called her adviser Charles - now Lord - Powell soon after resigning to ask what she should do as she had a plumbing problem. Call a plumber was his advice. Easier said than done for a leader who'd spent the past decade simply picking up the phone and asking "Switch" - that's the name for the Downing Street switchboard - to get Mr X or Mrs Y on the line. Tony Blair may have to be told today of the "new" telephone dialling codes.
UPDATE 1128: The Palace have been on the blower. Hands will not actually be kissed today. New prime ministers did once do it and the expression "kissing of hands" remains. The movie The Queen is - shocking to relate - not 100% historically accurate.
For a few minutes this afternoon Britain will have no prime minister. The moment will come after Tony Blair informs Her Majesty the Queen of his resignation and before Gordon Brown kisses her hand to mark his acceptance of her invitation to form the next government.
By historical standards this is a mere blink of the eye. When Churchill stood down it was a full day before Eden took over, leading the newspapers at the time to complain that Britain was leaderless. When Lloyd George resigned, it was a full four days.
Technically, there will briefly be no ministers either, for when a prime minister resigns he tenders the resignations of all his colleagues at the same time. In practice, those who were ministers will remain in post until a new prime minister has been appointed and has formed a new government.
In an era when we've grown used to prime ministers being on call 24/7 it is intriguing - if admittedly trivial - to speculate how government would respond to attack during the gap.
I am told that two ministers are always designated to press the nuclear button if necessary so Britain could respond without a prime minister. Of course, Her Majesty would be likely to speed through the kissing of hands with Gordon Brown to allow the new man to take charge.
What, though, if Brown had an accident on the way to the palace? Would Tony Blair be asked to reconsider? Or would John Prescott step in as deputy prime minister or Harriet Harman as the new deputy leader of the Labour Party? Take your pick.
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