I start my book with a short story about the time my grandmother walked all the way to my elementary school in Skokie, Illinois on a cold, windy day to “pick me up” and walk me back home. I was sick—not the “fake sick” kids sometimes feel, but the real sick, the kind that left me a little bewildered and scared and reluctantly headed to the nurse’s office. The nurse was kind, but insisted on calling home to talk to my parents. I already knew what would ensue—an awkward exchange between the nurse and my Korean-speaking grandmother, followed by the nurse handing me the phone with a look of confusion. I took the receiver from her and spoke to my grandmother, who immediately dropped everything and walked to school to come get me. My parents were both at work. What else was she supposed to do? We walked home together. And it is the first time in my life that I can remember feeling that I needed to protect my grandmother as much as she protected me. That is a very big feeling for someone so...