Imagine for a moment that you are to receive a major award. You have taken considerable care with your appearance. Your notes of appreciation, written in a wryly self-deprecating tone, are in your hand. You are just about to be called forward before the distinguished assemblage. And at that moment the friend standing next to you points out that there is a piece of toilet paper stuck to the bottom of your shoe.
You are chagrined. You are embarrassed. But better that your friend should have pointed that out now than you should have walked to the dais with a streamer of toilet paper trailing from your foot.
The friend who pointed out that piece of toilet paper is like your editor, the person who can tell you things you need to hear.
Your editor is not there merely to fix typographical errors, lapses of fact, mistaken homonyms, and other minor infelicities, though that is an essential part of the duty. Your editor's fundamental purpose is to keep you from making an ass of yourself in public.
That is why your editor is the person who tells you that you have gone through six paragraphs of throat-clearing before you say anything the reader might want to hear.
That is why your editor will point out that your tone is a mismatch for the subject, the occasion, or the reader.
That is why your editor is the person who gets to ask, "What's your point?"
That is why your editor can tell you, gently but firmly, that you are not as funny as you think you are.
That is why your editor may occasionally hear you say, "You said what I meant better than I did."
If your editor is not doing these things, you need to get a better editor.
If your editor is doing these things and you are disregarding them, or at the very least not discussing them, then you are a fool. And you will pay the consequences, not your editor.
That is why I tell you: Keep your friends close, but your editor closer.