Each college student is different, so there’s always different reason why they struggle. I work with college students around the country to provide support and help them when they’re not ready for college. I’d say the 2 most common contributors are: 1) challenges with self-regulation and the many ways this manifests (inability to start work, get to the library, work early or long enough, social issues, etc.) and 2) not knowing what it takes to succeed in college…mostly because high schools cater to students but once they get to college it’s mostly lectures, notes, textbooks, papers, and tests.