Fair enough. But a lot of these saying are written specifically to convey said (sometimes complicated) wisdom in the most simplistic way possible; and in this sense: it is very effective. A lot of things are written, more-so, to be impactful rather than sensical. Apple's famous "Think Different." slogan comes to mind. In fact, I'm pretty sure there's a technical term for this practice, that they teach in high school, that I've long-since forgotten. My point, in is essence, if I had to boil it down to such: would be that language can be used as an artful tool, just as much as any other medium. You can use its structures and methods (arguably improperly) to create new and valid things. The construction of metaphors is a practice in doing exactly this— not necessarily in the deconstruction of grammar, but in the purposeful manipulation of meaning.