The book is very big about Doing What Works For You, rather than having anyone subscribe to a particular set of rules. It's all about trying new things and looking at things from a new viewpoint, erasing the consumerist mindset that's been ingrained into everyone and believing that there really IS very little you NEED to buy.

But I just know that, if I had bags like that, I'd always forget to bring them to the store.
This is my problem, because I DO have bags like that, and I've ALWAYS forgot them. And I'm totally sick of the bags they give you, and you're right, they do put an absurd lack of stuff in each bag too.