"What I find to be very bad advice is the snappy little sentence 'Write what you know,' ...It is the most tiresome and stupid advice that could possibly be given.  If we write simply about what we know, we never grow.  We don't develop any facility for languages, or an interest in others, or a desire to travel and explore and face experience head on.  We just coil tighter and tighter into our boring little selves.  What one should write about is what interests one."