So I'm looking at the reviews for some waterproof pillow protectors on Amazon, and I notice a few of the one-star reviews say that the protectors aren't really waterproof. And after reading them, I find out that by waterproof, they mean pee-proof. Apparently the pillow protectors do not stop urine from soaking through onto your pillows. This is news to me. When something says waterproof I think they mean liquid-proof. Apparently pee isn't liquid. Or water. It's pee, and waterproof protectors should be able to protect against it when they say "waterproof." I'm so confused. And also wondering who is peeing on their pillows.