The metaphor is not original with me, but moods have the quality of the weather. I've been experiencing changeable weather the last couple of weeks. Like the weather, moods are notoriously difficult to describe. In my case, I go from a kind of nervous distraction in which I cannot work but cannot rest, either, to a kind of generalized sense of well-being during which I can focus & even write. But it's difficult to sense why I shift or when a shift is coming. The best I can do is be mindful of the state of mind I'm in at a particular moment & let go of it if it is not productive or at least comfortable.