Living in the West, it is easy to forget the fact that there are other language systems that do not follow the left-to-right reading structure present in English. Arabic and Hebrew follow the opposite direction, and so for them, the sense of progressing from past to future is associated with moving from right to left, not left to right. Chinese, Korean, and Japanese can be written from left to right or from top to bottom and so these cultures have a more fluid temporal-spatial relation. Further, aboriginal cultures that map their sense of time to the sun's path across the sky have different compass directions attributed to the past and future, depending on time of day.
This is just one such example by which Don Norman in his bestselling book, The Design of Everyday Things, recalls our attention to and critically examines the behavior models and objects that have become invisible to us in their everyday ordinariness. After reading this book, you'll notice your next interaction with door handles, faucets, stove burners, light switches, and pennies. Yet this book's message is not unique to material objects - it underscores the universal thought process required to design all objects, both material and digital. For lessons on digital designing specifically, check his well-maintained Nielsen and Norman Group site.