Love/hate relationship

It is rare that I have a love/hate relationship with books, but it does happen.  I feel this way with The Hunger Games.  I finished the first book and could not put it down but I finished the book feeling unfulfilled.  Sad for the characters in a way because I knew there was no way they could be happy.  Well I started book two, Catching Fire, and this only confirms my feeling, I will finish this entire series, but I know it cant end with a pretty little pink bow all tied up in a nice package.  So sad!  Some books don't have happy endings, shoot life does not always end happily, but I feel like books are such a nice escape for the everyday world of sadness, fighting, sickness.  Anyway, I think it is obvious the book is filled with passion and desire, so I have no doubt I will finish the series.  But I have definitely struggled with how these books can finish with me still loving them....only time will tell!