Instead, he addressed at least 250,000 – most of whom were under 40 and who waited hours to hear the young Democrat from Illinois tell them he came as "a proud citizen of the United States, and a fellow citizen of the world."
Senator Obama's main themes were about countries and cultures coming together, and drew on the strong historic ties between the US and Germany. It was partly a paean to the city of Berlin where the cold war wall came down, partly a warning that the "greatest danger of all is to allow new walls to divide us from one another," and partly a call to Europe to do more to end the war in Afghanistan.
His 30-minute speech got immediate laughs as Obama, whom some Germans have hailed as this generation's John F. Kennedy, started off by saying, "I know that I don't look like the Americans who've previously spoken in this great city."
The greatest response in a crowd that stretched for nearly a mile from the Siegessäule victory column to the Brandenburg Gate came as Obama went on a riff about bringing down walls, saying "The walls between races and tribes, natives and immigrants, Christians and Muslims and Jews cannot stand. These now are the walls we must tear down."
Security was tight. Crowds waited 45 minutes to have bags and bodies checked for metal. Open-pit BBQ and drink stands ringed the venue. A reggae and a rock band opened for Obama, and with a young backpacking crowd wearing sandals and T-shirts, the atmosphere was like a rock concert waiting for a foreign policy speech. German children danced around ahead of the speech in the Tiergarten, Berlin's rendition of Central Park, singing out "Obaaama, Obaaama." Such is the popularity here of the Democrat's presidential nominee, where the most influential news magazine, Der Spiegel, has dubbed him "president of the world."
Tens of thousands T-shirts handed out by the World Wildlife Fund showed a polar bear pointing his finger out, like Uncle Sam, and saying, "I want you to tackle climate change." The bear is saying in a dialogue bubble, "Yes, we can."
Germans and Europeans have focused strongly on the environment and climate change. Probably the second greatest audience response came when Obama pledged to "act with the same seriousness of purpose as has your nation, and reduce the carbon we send into our atmosphere... This is the moment to stand as one."
Ahead of the event, some German foreign policy elites were hoping Obama would speak in depth on Afghanistan and Iraq, issues that many German and European politicians won't address for fear of their unpopularity. Yet apart from some passing phrases and mentions, Obama did not go in depth into either the war he supports – in Afghanistan – or the one he doesn't, in Iraq.
"I recognize the enormous difficulties in Afghanistan," Obama said, as people in the crowd shouted his name and held up babies. "But my country and yours have a stake in seeing that NATO's first mission beyond Europe's borders is a success. For the people of Afghanistan, and for our shared security, the work must be done. America cannot do this alone."
Comment by German media after the speech suggested a temperate approach was the difference between a candidate Obama and a president Obama.
"I wanted him to talk longer about the two wars in the world right now," said Georg Stelzer, a 19-year-old wearing a surfing T-shirt. "And I would like to know how we are going to get out of them."
But for most Germans, many of whom came from several hundred miles away, the main attraction was simply to get a glimpse at a candidate they read about in the German press every day.
"I'm pretty young," said one college student walking with her boyfriend, who was asked what she thought of Obama's comments. "I don't know about the speech. I came here to see Obama.