I've always believed in writing without a collaborator, because where two people are writing the same book, each believes he gets all the worry and only half the royalties.
There was a moment when I changed from an amateur to a professional. I assumed the burden of a profession, which is to write even when you don't want to, don't much like what you're writing, and aren't writing particularly well
The best time for planning a book is while you're doing the dishes.
Plots come to me at such odd moments, when I am walking along the street, or examining a hat shopsuddenly a splendid idea comes into my head.