Emergency TP is also a good idea if you live communally with roommates. Inevitably, YOU will be the only person who ever buys TP BEFORE the last roll runs out. It saves a lot of grief (and paper towels/Kleenex/old term papers) if you stash one or two rolls away, and produce them only grudgingly, after reminding your buddies that it's their turn to be seen purchasing butt-wipe at the grocery store. If your "buddies" are really "dirty assholes" (so to speak), these rolls can be kept hidden and used only by you, while they rasp themselves on shiny Pizza Hut fliers.