The idea of back-to-school shopping shouldn't become obsolete when you reach adulthood. Whether or not you're gearing up for another year of classes (or just the end of your company-sanctioned summer Fridays), fall is the perfect time to stock up on practical — and adorable! — items that will get you organized. Sure, you may not be buying a new Lisa Frank Trapper Keeper or a rainbow set of gel pens, but you won't regret taking advantage of new merchandise and indulging in a planner or chic backpack. Click ahead for the 15 back-to-school staples you should still be buying, no matter how old you are.