Never think about the story when you’re not working.
“Hemingway says never to think about a story you are working on before you begin again the next day. “That way your subconscious will work on it all the time,” he writes in the Esquire piece. “But if you think about it consciously or worry about it you will kill it and your brain will be tired before you start.” He goes into more detail in A Moveable Feast:
When I was writing, it was necessary for me to read after I had written. If you kept thinking about it, you would lose the thing you were writing before you could go on with it the next day. It was necessary to get exercise, to be tired in the body, and it was very good to make love with whom you loved. That was better than anything. But afterwards, when you were empty, it was necessary to read in order not to think or worry about your work until you could do it again. I had learned already never to empty the well of my writing, but always to stop when there was still something there in the deep part of the well, and let it refill at night from the springs that fed it.”
Source: Open Culture