You manage your own time. You can count on parents and teachers to remind you of your responsibilities and to guide you in setting priorities. You will be faced with a large number of moral and ethical decisions you have not had to face previously. You must balance your responsibilities and set priorities. You arrange your own schedule in consultation with your academic adviser.
Schedules tend to look lighter than they really are.
Teachers carefully monitor class attendance. Professors may not formally take roll, but they are still likely to know whether or not you attended. You are provided with textbooks at little or no expense. You are not responsible for knowing what it takes to graduate. Graduation requirements are complex, and differ for different majors and sometimes different years.