I think I'm having some sort of Elijah and the cake episode in my shower- I keep using my shampoo, but it somehow never runs out. I've been working on this one bottle for... let me count, eight months now, and there still seems to be plenty left. Same goes for the laundry detergent that's probably a year old by now. It's not like I bathe and do laundry infrequently or with small portions of these cleaners. I don't know where it's all coming from.
My educated guesses thus far include product pixies and/or wormholes that lead to entire dimensions of shampoo and detergent.