I expect most (if not all) languages have figures of speech that, just like "improper nouns", tend to mean something only tangentially related to the literal wo

I expect most (if not all) languages have figures of speech that, just like "improper nouns", tend to mean something only tangentially related to the literal words. Whether most people can recognize and/or understand a novel one immediately likely varies though. I would agree that you tend to notice this more when learning a different language: As a child, you don't understand many things adults say and pick up these phrases among a lot of other inexplicable language. But when you later learn a new language, any apparent contradictions between the meaning of individual words and their combinations stick out much more.