>Bahnhof verstehen (transl. to understand "train station") derives from the German language idiomatic phrase "Ich verstehe nur Bahnhof" – I only/just understand "train station" – meaning to not be able, or perhaps not willing, to understand what is being said. It has the equivalent meaning to the English language idiom "It's all Greek to me".[1]

The curious case of the "... rest of this stuff it's English to me." reported as been said by a greek in the US:

https://www.texasbar.com/AM/Template.cfm?Section=Say_What_&T...