how could i leave this job undone?

You should go here and read B’s giant panda story.
I know how the protagonist feels. But for me, it’s standing on the pavement outside the fabric shop, thinking about just getting on my bike and riding and riding and never coming back. Then thinking of my poor students’ papers piled up on our dining room table, and how they’ve all tried so much harder with this assignment, and obviously all studied their guts out for the quiz. How could I leave this job undone?