Former first lady Michelle Obama’s memoir “Becoming” has become the fastest-selling book of 2018 at Barnes & Noble, surpassing the Trump administration tell-all “Fear: Trump in the White House” by veteran journalist Bob Woodward. In addition to being this year’s fastest seller, Barnes & Noble also announced that “Becoming” had the best first-week sales of any adult book since 2015’s “Go Set a Watchman,” the highly anticipated second novel from “To Kill A Mockingbird” author Harper Lee.