Crazy rhythm, or The Postpartum Polka

It happens this way most of the time: I finish a project with great excitement and exhilaration. I'm done! I did it! It works! But in the next day or two, a cloud nudges all this away and I'm asking myself, Yes, it's done -- but was it worth it? Does anyone actually give a damn? Is this all there is? And then, in the next day or two, I turn to a new project with all the excitement and passion of the serial monogamist. And I'm off and running. No wonder so many writers become mad.