Before Saidu dies Beah remembers that Saidu had spoken about parts of him slowly dying each passing day. Why would he say that? Do you think he is right?

Saidu laments that he is always expecting death. People come at him with the intent to kill and, even though he live, a part of him dies, 

"How many more times do we have to come to terms with death before we find safety?' he asked. 'Every time people come at us with the intention of killing us, I close my eyes and wait for death. Even though I am still alive, I feel like each time I accept death, part of me dies. Very soon I will completely die and all that will be left is my empty body walking with you."

I think his metaphor is correct. Everyday these boys live seems like they are living on borrowed time: they just exist in a very unforgiving environment. Little did Saidu know that his words would become prophetic.