I also learned, from my dearly departed mother, that dried herbs and ground spices have an indefinite shelf life. She taught me this as she reached for her 8-year old jar of cinnamon, stored in her spice rack over the stove.
But seriously, folks, anyone who has purchased products from Anson Mills, be it rice, polenta, grits, flour, oats, etc. has undoubtedly noted this instruction for how to store their products:
Please refrigerate or freeze upon receipt.