When You Reach Me question

At the end of this book a lot was resolved. For example, the reader finds out why Sal was punched by Marcus,(to seem tougher), we found out the Sal wasn't ignoring Miranda because he got punched, but because he wanted some more friends, and the reader finds out about time travel. The time travel aspect of the story is a huge deal, so much is resolved. For instance, readers find out that Marcus is actually the crazy man on the corner, that has traveled through time in order to save Sal from getting hit by the bus. In addition, Marcus was the one leaving Miranda the notes giving her clues as to who he really was. This is so important to the book and resolves everything.