A backpack is read as the load you carry on your own back — duties, memories, plans. Tradition sees a light one as freedom to explore and a heavy one as a burden to set down.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.