Re: German exchange officers, we had a German engineering officer at Marham and on being shown into his office for the first time, discovered a beach towel draped over his chair.
His English was very good but he always carried a dictionary around with him. After I'd written a short "bio" on him in the section's equivalent of Private Eye, he came up to me clutching the dictionary and asked "vas is follically-challenged?" Luckily, he did have a very good sense of humour.