I'm always a little irritated when people try to translate untranslatable proverbs and the like into another language, word-for-word. Way too awkward. "Neither fish nor meat." What? Probably the best approach is to say "There is a Russian (French, etc.) proverb meaning ......" That gets rather long-winded, though.
Perhaps there's a reason why the people from the translation agency never called me back about the job!
In the meantime, I'm going to break my own rule and translate a Russian proverb, just for fun.
"Назвался груздем-полезай в кузов."
Since you've called yourself a (particular kind of) mushroom, now climb into the basket.
See what I mean about awkward? The meaning relates to putting your words into action.
Such are my deep thoughts for the day.