In order to balance an equation, why can you never change a subscript?

Explain the effect of the rhetorical questions for the below paragraph. "i pinched myself: was i still alive? was i awake? how was it possible that men, women, and children were being burned and that the world kept silent? no. all this could not be real. a nightmare soon i would wake up with a start, my heart pounding, and find that i was back in the room of my childhood, with my "