“A Gentleman’s C,” a very short story by Padgett Powell—
My father, trying to finally graduate from college at sixty-two, came, by curious circumstance, to be enrolled in an English class I taught, and I was, perhaps, a bit tougher on him than I was on the others. Hadn’t he been tougher on me than on other people’s kids growing up? I gave him a hard, honest, low C. About what I felt he’d always given me.
We had a death in the family, and my mother and I traveled to the funeral. My father stayed put to complete his exams–it was his final term. On the way home we learned that he had received his grades, which were low enough in the aggregate to prevent him from graduating, and reading this news on the dowdy sofa inside the front door, he leaned over as if to rest and had a heart attack and died.
For years I had thought that the old man’s passing away would not affect me, but it did.
(From Micro Fiction, edited by Jerome Stern).