GEORGE R. R. MARTIN is in his element. Pen in hand, wearing his signature wool flat cap, he’s seated in a corner of the cavernous San Jose McEnery Convention Center, site of this year’s Worldcon — the World Science Fiction Convention, held annually since 1946. A long line snaking around stanchions inches forward. A hundred people, maybe more. A member of the convention staff stands near the table, explaining ground rules: one book at a time. If you want multiple books signed, you must go to the back of the line. Martin, 70, banters with the young woman standing across from him as she proffers a hardcover bearing his name, her demeanor part reverent, part sheepish, the latter perhaps owing to the fact that this is her fifth or sixth time through the line. I’m trying to maintain a loose orbit around the author, the optimal distance to watch him without being creepy. His publicist takes me toward the queue. We wait until the book-bearing customers have exhausted their requests, and then all of a sudden I’m standing in front of the man. “Don’t be a fanboy,” I tell myself, trying to keep my cool as I explain that I’m…