Wikipedia has a lengthy section about this 'gaffe', including the likely origin: https://en.wikipedia.org/wiki/Ich_bin_ein_Berliner#Urban_legend https://en.wiki

Wikipedia has a lengthy section about this 'gaffe', including the likely origin: https://en.wikipedia.org/wiki/Ich_bin_ein_Berliner#Urban_legend https://en.wikipedia.org/wiki/Ich_bin_ein_Berliner#Urban_leg...