We all did it when we were in school - we would dutifully go home, check our planners and rejoice when there was not an assignment to be done. We'd enjoy the evening, hang out with friends, and kill time until we inevitable went to sleep at 1 am anyway, only to arrive at school the next morning and discover that there was something due! We just hadn't written it down, and our grades suffered as a result.
For most students, this is the occasional result of being in a rush to get out of class. But for some students, like the one discussed at the beginning of Providing Student Reminders, Protecting Student Privacy, this forgetfulness is rooted in a more serious issue. For students with special needs in mainstream classrooms, or with behavioral disorders like ADD, the inability to think ahead or write down assignments is what puts them in hot water academically (not a lack of intelligence or poor understanding of the course work). This is where technology-based reminders can help to save a student.