Basically you come up with the fictional idea and you start writing that story, but then in order to write it and to make it seem real, you sometimes put your own memories in. Even if it's a character that's very different from you.
Jeffrey EugenidesShe lost much of her appetite. At night, an invisible hand kept shaking her awake every few hours. Grief was physiological, a disturbance of the blood. Sometimes a whole minute would pass in nameless dread - the bedside clock ticking, the blue moonlight coating the window like glue - before she`d remember the brutal fact that had caused it.
Jeffrey Eugenides