I'll take it a step further and ask, do adages actually contain any signal at all? If you have a saying "try try again" and another saying "don't bust your head against a brick wall" which one wins? When?
Getting fluent in French is probably best done without a plan, but just practicing a bunch. But I'm sure you can think of several activities where "just try it" is godawful advice. Who says writing is in the former camp? Prove it.