JFK Accidentally Called Himself a Jelly Donut in Berlin

The sentence was correct, and nobody laughed. In German, when you say you belong to a city, you typically drop the article, so 'Ich bin Berliner' would be the literal 'I am a citizen of Berlin'. But Kennedy was speaking figuratively, in solidarity, not claiming citizenship, and in that sense adding 'ein' is grammatically fine and arguably better. Crucially, Berliners did not even call the pastry a 'Berliner'; in Berlin it was a 'Pfannkuchen', so the pun would not have landed there anyway. The crowd of hundreds of thousands roared its approval; there is no contemporary report of confusion. The doughnut gag only surfaced decades later and snowballed online. So one of history's most famous gaffes is not a gaffe. Kennedy said exactly what he meant, the city understood, and the joke was invented long after everyone went home.