You'll cry your way through this, cover to cover. BUT...you will remember this book forever. It is beautiful. I know that it got quite a bit of attention when it first came out which can mean two things: a) it really is a fantastic book or b) it's the literary equivalent of Twilight...no offense. Twilight has its merits, but "thought-provoking" is not among them. This book has that.
I suggested this book to a friend who finally read it... rather reluctantly. It's now her favorite book. You will gain a lot of insight from reading this and really start spending more time considering how your life intertwines with the lives of the people you meet, if only in passing. Who have you met today and how could you have changed their life? Think about it.