Contra Costa Times:
"DEAR MISS MANNERS: Since I began receiving disability income several years ago, I have often been asked what I do for a living. My disability has very personal aspects, and I sometimes do not feel comfortable talking about it. I have tried replying that I am writing a book, but many people are not satisfied with that answer. Would you please suggest a polite way to deal with this inquiry?
Gentle Reader: Not satisfied with "writing a book"? Why, Miss Manners can hardly think of a more respectable occupation that has no visible results for years. Try, "I'm writing a screenplay." Most Americans are. Besides, that counts as true even if you have only gotten to the stage of walking out of movie theaters thinking, "I could put together something better than that."