‘You can create people in your mind that you get excited about; you can devise and develop a plot situation, you have a sense of structure and form; and you can write readable narrative and dialogue. Thus equipped, you can write good stories, but it doesn’t follow that you can write good detective stories. For them you need something more.
You need, not the kind of mind that likes to solve puzzles, but the kind that likes to construct puzzles, which is quite different. You also need considerable ingenuity if they are to be not only puzzles but good ones.’
— Rex Stout