Still Don't Get It

I read to the end of the book and I still don't get it. The last chapter is weird in a savage way and it is kind of sad and everything happens so suddenly. it is really shocking that by the end of the book, before they get rescued, they are all savages that kill each other, besides Ralph and Piggy. They are the only sensible ones. To think, also, that they were a group of 12-year-old choir members that turned savage. It also never explains where the dead guy in the parachute came from. It also doesn't explain if the beast was real or who the Lord of the Flies is or if he's real. As a matter of fact it doesn't mention the Lord of the Flies at all after the conversation with Simon.


P.S.
In my post titled: The Lord of the Flies: The Confusing Stuff , when it says they can roll rocks onto the bridge of the fort (the fort is just a pile of rocks that is connected to the island by a "bridge" of rocks) they end up using it as a weapon. They roll rocks down the bridge if they see an intruder coming. I forgot to tell you that when I say "they" I mean Jack and the other "biguns" that turn into savages. Ralph, Piggy, Sam, Eric, and the "littluns" are the other faction. Simon doesn't chose a side. They split up into these factions by the end of the book, and in the last chapter Ralph is all that's left of his faction. All the "littluns" join Jack, and Sam and Eric too.