In the dream to see a knapsack, represents that you will find your greatest pleasure away from the associations of friends. For a woman to see an old dilapidated knapsack, indicates poverty and disagreeableness for her.
Dream dictionary: Knapsack dream meanings
If you see a book bag in a dream, then it represents your desire for newness. If you wish to get the better interpretation of your dream, please see the meaning of Knapsack.