The curse of every teacher's life. Marking is that all too familiar process which takes place when one is faced with a pile of papers of dubious quality, which must be tactfully graded within a strictly controlled bell-curve range, and commented upon in such a way as to encourage the student, while still justifying the grade.
At the end of any semester teachers trudge their way through this task, in disillusion and disheartenment, as they realise from the frequently abysmal assignments in front of them how few of their students have paid even a modicum of attention in their class, and despairingly acknowledge that it is unlikely that more than one student in ten will actually read their lovingly crafted commentary, having once ascertained that they have passed the course. Failure to provide said commentary, however, will inevitably lead to complaint being made to one's head of discipline and the acquisition of a reputation for slackness.
This node brought to you by the Gods of Marking Procrastination