When I was taking my very first CS class—almost three decades ago—the lecturer recommended David Harel's book Algorithmics: The Spirit of Computing:1 "If you want your friends and family to know what you are doing here" he told us, "let them read this book." A wonderful piece of advice, still applicable today, which enabled me to share my budding love for CS with others, but also helped me further my own understanding of "what we are doing here."
Many years later, our understanding of the Theory of Computation (ToC) has dramatically grown and the field is thriving. I find myself yet again with the opportunity to share my love of the riveting notion of computation. Since Avi Wigderson's Mathematics and Computation: A Theory Revolutionizing Technology and Science,2 was published recently, I have been recommending it to anyone who showed an interest in ToC. But I also recommend it to my fellow theoreticians, who study ToC, because Mathematics and Computation is a way for us too to better understand what it really is that "we are doing here."