Lord of the Flies, by William Golding, is set on a tropical island; the characters are all English schoolboys ranging in age from five or six to thirteen or so. The last paragraph of chapter five refers to Percival, one of the littlest boys on the island.
Simon, Piggy and Ralph are afraid about the dramatic changes which are happening on the island and the fact that none of the boys has been sleeping well because of their nightmares about beasts and other things. The three older boys long for the civility which they knew back in England and are convinced that if someone from that polite adult world would just send them some kind of a message, everything would be fine. (Ironically, a sign from the adult world does arrive in the next chapter, but it would not have encouraged them even if they had seen it.)
Their conversation is interrupted in the last paragraph of the chapter:
A thin wail out of the darkness chilled them and set them grabbing for each other. Then the wail rose, remote and unearthly, and turned to an inarticulate gibbering. Percival Wemys Madison, of the Vicarage, Harcourt St. Anthony, lying in the long grass, was living through circumstances in which the incantation of his address was powerless to help him.
Just as the boys are yearning for the civilities of their past lives Percival, one of the littluns, is crying in his sleep, undoubtedly from bad dreams. The narrator notes that nothing about Percival's proper English upbringing (which is the answer to all the problems on the island, according to the older boys) is able to quiet the fears that haunt him during the night.
By the end of the novel, Percival tries to tell the naval officer his proper name and address, but he cannot do it. Any vestiges of his past life have been erased by the savagery of his island experiences.
I think it has something to do with the fact that they thing Percival screaming is the beast, and therefore are scared of it. In a literal sense, it is not the beast. However, because the beast is inside all of the boys then, ironically, they have been scared by the beast.
Also, when a child gets lost they will know that to get back to where they know they can tell an authority figure their address and they will take them home. This is sort of linked with the innocence of a child. However, on that island their is no innocence and so he cannot be saved by the "incantation of his address".
These are only my thoughts and should not be taken as the one and only correct answer