Her bereft daughter composed a heartbreaking goodbye in the Notes app and shared it with the world. Then, on Twitter, I came across a tribute to Eva Mireles, the 4th grade teacher who died trying to shield her students from an 18-year-old reportedly armed with an AR-15-style rifle. I'd seen a version of this happen so many times before. Distraught yet desensitized, I couldn't express grief. After learning that a gunman murdered 19 children and two adults at a Texas elementary school, it took me nearly 24 hours to weep. Becoming numb is inevitable when living in a country that makes killing people easy.