A manager was standing there, so I talked to him about the discount. He explained to me that the purpose of the discount was to encourage customers to bring their own bags. I asked him why the store wanted people to bring bags. He said that it saves the environment, just as I figured. I asked him, wasn't I saving the environment equally if I were to carry my items in my hands or if I were to put them in a reusable bag? He told me that the store's policy was that I needed to bring in a bag for my items to get the discount. I told him that I had been offered a bag, but declined, as I don't like to waste things. He then informed me that the bags are recyclable. Um, yes, but they require energy and resources to make and energy and resources to recycle. Not taking one at all saves exactly the same energy as putting my items in a bag I've brought in. He agreed, but said that I had to have a bag with me to get the discount.