As your English professor also should have told you, words used creatively are not the same as words used in making documents or college papers understandable to people who really don't want to read them. Keeping things simple is not always the best course of action, especially when dealing with fiction. Creative writing is the expression of ideas and emotions and imagination through words. And if you have ever taken a Creative Writing course, college or otherwise, you would have been taught that sometimes using flowery language or ostentation as you put it can enhance a work."Two sides of the same coin" is something that we learn in grade school in most cases. Talking to someone on the street, you would certainly use it to keep the language flowing easily. If you were writing a paper for college - up to a certain level, depending on the degree (Mine is English Literature) - you would use it. You would likely be marked off for using something so obvious and overused, but that's neither here nor there.Art and literature are supposed to stimulate, not tranquilize. Sometimes you are meant to be challenged, not see the same thing over and over again. If something makes you think or look it up? Great. You learned something new today. The use of strong words and phrases are more likely to bring out an intellectual or emotional reaction than a simple, well-known phrase. This is what good writers strive for, in the end. Getting a reaction from the reader.Also, your analysis that it means "two sides of the same coin" is not entirely accurate. There is another piece to anaphora and epistrophe, where "two sides of the same coin" wouldn't fit. Sometimes... Complexity has meaning beyond the desire to be complex.