A student took the final late, due to family issues. He was passing before he took the final, but a 26% on the final changed his grade to an F. Because the exam had to be put in the Assessment Center, I took two trips there for his final. Why didn’t he study? There is no way he could have done that badly if he had actually studied, not with C level work before the exam.
Perhaps he believed that he knew the material. Perhaps the family issues were too upsetting for him to study. But he might have been better off if he did not take the exam. He might have been able to persuade someone that the family issues were important enough for him to be allowed to take the final exam weeks later, but he ended up wasting both of our time.