Because you're always buying toilet paper in bulk, and everyone needs it.
Toilet paper is cheap and bulky, so stores only stock what they absolutely need. If a store is supplied once a day, it'll have something like two day's worth of toilet paper on its shelves.
Some incident happens, and people start to panic. By sheer coincidence one brand of toilet paper happens to be out of stock. The shelf space is huge, so as you walk past it you immediately notice it and think "geez, wouldn't it be awkward if that were to run out". You don't know how much you've got remaining at home so you grab a pack, just to be sure. Ten people do this, and because the packs are so massive another brand has just run out - making even more people consider picking up toilet paper.
You normally buy toilet paper maybe once every month, so if only 1 in 15 people pick up toilet paper during their panic shopping, those two day's worth of stock will quickly run out!
Toilet paper is cheap and bulky, so stores only stock what they absolutely need. If a store is supplied once a day, it'll have something like two day's worth of toilet paper on its shelves.
Some incident happens, and people start to panic. By sheer coincidence one brand of toilet paper happens to be out of stock. The shelf space is huge, so as you walk past it you immediately notice it and think "geez, wouldn't it be awkward if that were to run out". You don't know how much you've got remaining at home so you grab a pack, just to be sure. Ten people do this, and because the packs are so massive another brand has just run out - making even more people consider picking up toilet paper.
You normally buy toilet paper maybe once every month, so if only 1 in 15 people pick up toilet paper during their panic shopping, those two day's worth of stock will quickly run out!