The crude question turns out to be fatal. You have never, it now appears, really understood what you have so long maintained. You haven’t really thought it out; not to the end; not to ‘the absolute ruddy end’. You must either give it up, or else begin it all over again. If, given patience and ordinary skill, you cannot explain a thing to any sensible person whatever (provided he will listen), then you don’t really understand it yourself. Here too it is very like doing Latin prose; the bits you can’t get into Latin are usually the bits you haven’t really grasped in the English.
