An antacid for writers

Writing a novel, even one that's never going to be published, has strange results on the cognitive functioning. Slowly one starts inhabiting two worlds, and as the writing progresses the second world begins to take over. In the early hours, when your semi-slumber is illuminated by strange juxtaposed fantasies, they are now located in the world you have invented, peopled by characters you have adapted from friends, relatives and celebrities. But all that changes as you cross from the creative (in the narrowest sense) phase to the editing. Now you wake to phrases and synonyms jostling for precedence, sometimes even struggling for survival as the razor sharp editing blade hovers mentally over your favorite paragraph. And once the manuscript is finalised and dispatched to an agent's slush pile, what then happens to the mental images, ideas and syllables. These have been created with real energy, so they have a real existence beyond the page. Do they just fade, or is there a digestive process that recycles the serviceable mental constituents and excretes the rest. (A cynic might say that this final stage was reached much earlier in the process, and manifested as a manuscript).