The balance of the universe is restored, as today a student informed me that they were having "flashbacks" to my course last semester. The word "nightmare" was used more than once.
Me: "Well, I hope you used your experience to warn future students away from my class!"
Student (chuckling): "No, I told them all to take it! It was really good."
I'm not sure if it's Stockholm syndrome, sheer sadism, or a third option, but I'm glad to see that my veneer of frighteningly demanding professorhood has been restored. (See a few weeks ago, when a student called me "benevolent".)
(On a more serious note, I am now awash in guilt and concern over the negative impact that my job has on student mental health.)