First of all, you have to give Dill credit for simply having a wild imagination--one that would probably help him become a writer one day. After all, author Harper Lee based his character on that of her friend, Truman Persons, who would later become the internationally renowned writer Truman Capote. Unlike Jem and Scout, who have rarely, if ever, been out of Maycomb County, Dill has seen a great deal of the southern United States during his short lifetime; much of it was done on his own, since his parents seemed to prefer spending their time without their son. Dill has seen Siamese twins in Bay St. Louis, Dracula in Meridian, and he claims to have even been to Canada (Nova Scotia). Jem and Scout are never sure which of his stories are true, since
Dill Harris could tell the biggest ones I ever heard.
Aside from his imagination, Dill spends much of his time alone, since his mother has been divorced, and she works, leaving Dill on his own during the day. He probably has few friends in Meridian, since Jem and Scout quickly become his closest pals, even though they are together only during the summer months. Dill tends to compensate for his lack of parental love and attention by making up "whoppers:" His new father is the president of a railroad, and he is the grandson of Confederate General Joe Wheeler. Dill wants to be accepted and he uses the guise of self-importance for assistance.
As for Boo Radley, his mysterious whereabouts and the many ghoulish stories about him helps to fuel Dill's imagination. Unlike Dracula, who Dill must recognize is fictitious, Boo is real if unseen, and the Radley House is never far from his sight. It is a mystery which Dill decides must be unraveled, and since there is little else to do during the summers in sleepy Maycomb, Boo becomes the dominant focus of Dill's imagination.