I like to have a little extra on hand so that I can add more "flair" to dishes. For instance, I am not limited to one type of sauce, etc.
I always have extra toilet paper... well, just because.
I never stockpile women's sanitary needs, but I really wish that I did.
I don't stockpile for the OMG THE WORLD IS ENDING PLANET X 2012 RECESSION stuff. I figure that if that ever does come to pass, having creamed corn in your closet isn't going to get you anywhere.