Learning the meaning of foreign language expressions

Do you know what a "thrave" is?

...OK, I was having you on; there is no such thing. But I think this helps to put forward my point that as human beings we have a definite ability to remember things even if we are unable to attach any kind of meaningful significance to them. Even though, in language, if we are going to learn new words, we prefer to see them actually used in context - in some sort of sentence, rather than just isolated on their own, like in a dictionary.

As a professional translator I feel privileged to be able to use a certain feature on http://www.translatorscafe.com that allows me to confer foreign language expressions I am at a loss to understand on my own, with other professional linguists all over the world. And when I do this, I always have in possession the very material that I am quoting it from - even if, as the title of a new insert in TranslatorsCafe, the expression always stands alone as it invites people to visit the discussion and offer their suggestions or comments. (They always ask for context, though.)

The French expression: "C'est en forgeant qu'on devient forgeron!" How many of you non-native French speakers out there would have guessed that this has nothing to do with blacksmiths or blacksmithing; but is what the French say when they mean to say, "Practice makes perfect!" But even that's seeing the phrase in isolation - maybe you would have guessed it had you heard in whatever French conversation?