Injury.
Yesterday I spent several hours tearing up carpet on the stairs between the first and second floor. I spent lots of time supporting myself with my left arm and pulling out about a gazillion carpet tacks with pliers (using both hands on the damned things). I managed to inflict some kind of trauma to my left hand, rendering my pinky and ring finger somewhat numb and only partially functional. Typing with those two fingers is still a chore and guitar playing is out of the question.
I hope it’s better by tomorrow.
I think I must be allergic to manual labor.