When you have finished a real effort of a major book [or music], you cannot start a major book the next day. At least you cannot start more than the first few pages. I usually make a start and then step aside and let the well fill up again. That’s also why I move from genre to genre. I never write two books of the same genre in a row. I think that’s a safety valve. If you write the same genre over and over again, you do tend to get stale.
– Madeleine L’Engle, Writers’ Workshop, Session VII, 28 January 1983