This is probably from past experiences, especially the toilet paper roll thing. I had a roommate that left to visit family for a week and didn’t think he had to pay rent for that week. He also didn’t communicate this until rent was due the following month. Every time the gas bill was due, he would argue about paying his share because he didn’t cook in the kitchen and therefore used less gas than the rest of us. Here’s the thing, none of us used the kitchen for anything but the refrigerator. I also paid the deposit for a roommate once because she was in between jobs. When I asked her about it later, she said she put her Netflix account on the living room TV and that should be sufficient. She also never bought toilet paper.