I think there's a fine line between preparation and panic, and it's sort of hard to tell when the former becomes the latter.  Preparation is buying groceries before a snow storm, when you might not get a chance to go shopping for a few days.  Preparation is having some non-perishable foods, water, and batteries in case of a power outage.  Preparation is not leaving dirty dishes in your sink when there's a storm inbound (lesson learned the hard way). 

Preparation is planned.  Panic is reactionary.  Panic is buying a bunch of toilet paper.  Panic is buying all the meat at the supermarket.  Panic happens when you see other people buying something and think, "Wait, maybe they know something I don't.  I should buy that too before there's none left."  Panic is irrational, and in a sense, unstoppable. 

Side note:  Honestly, what's with the people buying all the toilet paper during the coronavirus quarantine?  It's not even the right thing to panic-buy.  The right thing would be fresh food, but not more than you can eat before it goes bad.  Or canned food, or beans or rice or something.  But toilet paper?  Do they plan to spend a lot of time on the toilet?  Do they realize that's not even one of the symptoms of this viral infection?  It's a perfect example of an irrational panic-buy. #psychology