Open a vein into the mind of a writer at work, as he creates stories within stories,within stories. Watch as he figures out who his characters are and what they will do next. If you want to know what it really feels like to be an author, short of doing it yourself, this is probably your best chance.
It's not unusual for a person to be so preoccupied as to appear absent - but the point was that I wasn't absent. I was there, fully engaged in what was happening, and at the same time I wasn't there - for there wasn't an authentic there anymore. It was an illusory place that existed in my head, and that's where I was as well. In both places at the same time. In the apartment and in the story. In the story in the apartment that I was still writing in my head.