It can take a lot to silence a British reporter, but this is what happened when an ITN correspondent began to talk to the camera on the edge of the crowd in Prague's Hradcany Square on Sunday as Barack Obama was speaking. "Get him to stop," one young Czech hissed at me. "We haven't come here to listen to him."
As Air Force One climbed out of Istanbul yesterday, President Obama knew that during his eight days in Europe he had at least got people's attention, not just in Prague, but in Strasbourg, Istanbul and London too. From the time he touched down a week ago for the G20 summit, you could see his confidence grow as he absorbed the admiration of the crowds, of fellow leaders and headline writers.
The choreography, even without the surprise of his detour into Iraq last night, was masterful. Michelle Obama, who returned home after the Prague leg, both humanised and glamourised him, always proffering a cheek before the quick-shutter cameras. For flattery, each speech was peppered with allusions to local history. The Prague address invoked the founder of the former Czechoslovakia, Tomas Garrigue Masaryk, noting he had spent time in Chicago, Mr Obama's home town. In Strasbourg, it was Goethe.
Best of all, as far as European ears were concerned, Mr Obama played the humility card. Over and over, he told his audiences that he had come not to lecture but to listen and partner.
"He is the President that Europe always wanted for America," Katinka Barysch, the deputy director of the Centre for European Reform in London, said yesterday. "We could not have made it up any better ourselves."
It would be dangerous, however, if Mr Obama takes all this adoration at face value. In Prague, he saw the rapt smiles and tiny star-spangled flags, but he was not allowed to wander beyond the crowds and interview the chain of protesters in white robes and masks walking back and forth across the Charles Bridge all Sunday – the "invisibles" in the Czech Republic who oppose American plans for a missile defence base on the country's territory to protect the allies against any future aggression from Iran.
He did not have the chance to speak to Francesco Cerruti, a 20-year-old Italian student in Prague who, after getting up at dawn to get a good spot in Hradcany Square, left angry that the President had praised Czechs for agreeing to the base. "That is wrong to say that. The Czech government agreed but 70 per cent of the people are opposed," he said, citing recent polls. Mr Obama probably didn't glimpse the black smoke rising from fires started by protesters on the fringe of the Nato summit as he left Strasbourg either.
However, the President has created at least the spark of a new romance with Europe and that alone should be a source of satisfaction. But there are hidden perils in this courtship.
Had he seen the anger in Strasbourg or indeed on Threadneedle Street he might have grasped how wide the chasm remains between what Europeans and Americans consider as "decent capitalism". Even harder for him to see is how comprehensively Europe may be about to let him down with its special talent for cowardice, hypocrisy and inaction.
Consider Turkey and its place in Europe. How many people told me, after seeing Mr Obama these last few days, how thrilled they were that America had put a black person in the Oval Office? How fantastic to embrace diversity in this way. Yet, do they expect their leaders, by which I really mean French and German leaders, to heed his call to bring Turkey into the EU? Muslims taking decisions in Brussels – in our "little Christian club" as Ms Barysch puts it – isn't that taking diversity a bit far?
Perhaps the most striking of Mr Obama's speeches came in a cavernous basketball stadium in Strasbourg before an invited crowd of French and German teenagers where he offered Europe a deal: his election means that America will change its attitudes and foreign policy but Europe must change in turn. That requires an end to the "insidious" anti-Americanism. And if America is going to respect Europe's capacity for leadership more than it has in the past, Europe must show it can meet the challenge.
The President doesn't see how bamboozling this might be for European leaders, who for years have used popular antagonism against the US as a cover for running away from trans-Atlantic burden-sharing – not least in defence policy and in Afghanistan. Mr Obama is saying that the days of American unilateralism are over. That's nice, but it implies that Europe must actually deliver something now. So far it shows little sign of doing so.
At Strasbourg, Nato cobbled together about 5,000 new troops for Afghanistan, but most will be sent to help secure presidential elections in August after which they will leave. Some may suspect that Mr Obama might almost prefer to take full control of the AfPak mission against the Taliban and al-Qa'ida, but if Europe wants world leadership, this was not the way to do it. And for all the press spinning after Gordon Brown's G20 summit, it is clear now that most of what Mr Obama expected from Europe in terms of stimulus spending to rescue the world economy, he did not get.
It is clear that behind the scenes in Strasbourg and London, Mr Obama dazzled his peers by deploying his old community organiser skills to close rifts between leaders, some of whom he had never even met before. He soothed Chinese President Hu Jintao with a compromise on tax havens, charmed Dmitry Medvedev into agreeing to start new nuclear stockpile talks this year. Yet where are China and Russia today on North Korea and its missile launch? Not with Mr Obama.
If Mr Obama is naïve sometimes, it is hard not to admire him for it. He took risks in Europe, not least in Turkey – highlighting his own experience living in a majority Muslim country. (Indonesia when he was a child.) It will be seized on at home by the nutty right who still spread tales of him being Muslim himself, but the President decided the gesture was worth any domestic political cost. And just as Mr Obama reaches out now, it is also time for Europe to take a few risks.