Writers are frequently asked "Where do you get your ideas?" There are some flip answers: "a post office box in Schenectady"; "I keep a little old lady chained in the basement"; etc. The problem is that the question is too general. Ideas come from all sorts of places, and the writer doesn't know where all the ideas came from. But if the question is "Where did you get the idea for this story?" then there's a chance that it can be answered.