Once I walked into a little shop in Orvieto and announced "grazie" to two very confused sales clerks. No context — just this goofy American feeling overly confident with her newly-acquired four-or-five word Italian vocabulary, and stuttering out a completely incorrect greeting.
Cursed with blushing, I turned around, exited.
Once outside, I nearly fell down laughing.
And then there was that bakery in Paris, when I was twenty, that I visited daily for my croissants and baguette. Desiring something sweet, I asked for a Napoleon. The crowded boulangerie suddenly became very quiet, and the girl behind the counter delivered an arch glare.
What? Did I say something wrong?
She looked me in the eye and said, "Il est mort."
Whereupon loud bursts of laughter erupted from everyone in line.
"Mille feuille," she said, "a thou-sand-leaves."
I'd just ordered a dead emperor.