If I had a single backpack of things that I want with me, it would hold:
~My writing notebook for fiction, journaling, poems, lists...
~pens, pencils, colors, etc
~brightly colored sugar and creme (yarn)
~my crochet hook roll (that I made :D)
~some books, like The Hunger Games, or Maximum Ride, adventure-y/sci fi, or just a library card registered at enough places, assuming I was traveling
~OK, I would need internet. A laptop.
p.s. today i just got a new adidas sackpack [drawstring bag], and it's awesome. I'm eager to use it.