As an early Common Core booster, Michael Petrilli had hoped that by now--10 years after most states adopted the standards--the nation's schools would have logged tangible improvements in teaching and learning that resulted in higher student achievement. In this article, Petrilli reviews what Common Core is and discusses the work ahead that is required to raise standards for what it means for a student to be "on track" or "on grade level" in the quest for college- and career-readiness. Figuring out how to help these kids catch up, while encouraging their higher-achieving peers to continue making progress, is extraordinarily difficult. It will likely require new teaching strategies, the use of digital resources that allow for greater personalization, and other approaches that nobody has yet dreamed up. Common Core was part of a larger strategy to shift schools' expectations significantly higher. State assessments that were aligned to more challenging standards, and that set passing scores at loftier levels, help to make these expectations tangible. [For "A Decade On, Assessing the Impact of National Standards Has Common Core Failed? Assessing the Impact of National Standards," see EJ1247174.]