Admit it, sometimes you feel like this sometimes when you are grading an especially poor paper or exam. That red pen starts slashing just a little bit faster, and you press it against the paper just a tad harder. You know you covered this material in class and it's in the textbook! How could they not grasp even a tiny portion of it? Your frustration bubbles up a bit. Your grip on your pen tightens without your noticing. You normally don't look at the names on the tests whiles you're grading, but you can't help it. Oh yes. The student is that one that sits in the back playing with their phone. Sometimes they whisper something to the girl next to them and smirk. If it was the student who came to your office asking for help, the one who struggles to grasp the material despite their best efforts you'd feel bad. In this case though it feels, somehow, just a bit, as if it is just. "I am karma" you think, "I am justice. Your folly will cause you to meet your reward. Your GPA is about to take a hit. I ... AM ... DEATH!" You slash a big red "F" with a circle around it for emphasis on the blue-book cover. It is finished.
Then you move on to the next test. Oh good, this student gets it. You sigh, settle into your chair a bit more, and your grip on your favorite red grading pen relaxes a bit. Your breathing slows a bit, as does your heart. "Almost done," you think, "I am almost done."