Why is percival unable to remember his name and address?

Please help!! :(

He is one of the "littleuns". He is so traumatized by the events he lives through that he forgets what civilization is about, including his name.
http://www.bookrags.com/notes/lof/CHR.htm
"Percival Werthys Madison: This littlun would always give a full introduction of himself: 'Percival Wemys Madison. The Vicarage. Harcourt St. Anthony, Hants, telephone....' complete with address. He is one of the three attacked by rocks thrown by Roger and Maurice when building sand castles. By the end, when finally rescued by the grown-ups all he can say is 'I'm-- I'm--' before realizing he has forgotten his civilized identity. "

does ralph understand why he must be killed?

6 answers

civilization has been wiped away as has the name and address that was in his head when he was a part of civilization
what is the irony of Samneric's behavior in Chapter 12
They allow Ralph to pass them in the forest without telling the others and then the next day they are part of "the hunt" to kill Ralph
comprehensive grasp of the significant ideas of the symbol
what is the exact quote from the novel that says when percival forgets his name?
He says:
"I'm–I'm..."