You never made a big deal about it, because usually, I'd just reach for a new one from under the sink - YOU even know where it is, by now - and pop in the new one.
Yesterday, you reminded me again in the morning to put out a new roll, but as I was busy doing something else, I kinda mumbled, "okay, i'll do it later" and went off to bring the dogs out or something. During the course of the day, before we went out to town, I put a new roll up.
When we got home, you had to go to the bathroom, and I hear this excited shout..
"MUMMY! The toilet paper is puffed up again! How did it DO that???" :)