Grading is Bad for Sleeping

I was up late last night grading final projects, which is something I will be doing again tonight. I hate that. I think that post-grading dreams are worse than nightmares in terms of sleep quality. At least with a nightmare, part of one's sleep cycle is restful and stress-free. After grading, I end up grading in my dreams all night, and none of the papers make any sense at all. It doesn't matter how many times I wake up and go back to sleep, the entire night is spent grading nonsense, which would be okay if it was pleasant nonsense and I was happy about about it, giving all As. But no, I do not dream about A papers. Instead I get frustrated and keep repeating, "but it doesn't make any sense."