I believe the authors intentions for making this book was to inform people of the hectic things that happen in the world and not every child has had a childhood.
The theme really applies to Ishmael Beah. Beah was a small 12 year old boy and was separated from his family, left to take care of himself, and later recruited in by the rebels.
" I began to feel my ribs when I touched sides (Beah 44).
"There was a bullet hole in his forehead and underneath the stoop lay the bodies of two men...that was on the ground next to their piled body parts" (Beah 41).
Ishmael witnessed many dismembered and decaying bodies, so many to the point where he became use to them.