Whatever the idea or conceptual intention for your painting may be, perhaps the thing itself, when it comes, is always something of a surprise, even a shock (unless, I suppose, you find something you like doing and then just keep repeating it).
In response to that shock various things might happen. Your critic might rear up and start the judgement game. Your perfectionist might start her nitpicking ways. You might feel depressed, or dissatisfied.
But what if all of this was just an afterthought, a reaction to the surprise of creativity, the shocking reality of radical novelty? Perhaps we don't expect to shock ourselves, to find ourselves the source of something previously unknown.