Went for a run. After that I spent an hour on the YA book, and worked out the general outline of an ending. The problem had been, that I’d allowed my party of protagonists to split up and I needed a convincing reason for them to get back together in time to figure out and thwart the disastrous action planned by the villain. And I did, I see how it can all go down now. This was very satisfying. There is a positive endorphin rush that comes from working out a creative problem.
Then I spent another hour on Lisp. Then it was 11:30 and I went to FOPAL for a pleasant afternoon of sorting. I had meant to do four hours, but at 3pm my feet and back were hurting, so I called it a day.
In the evening I cleaned the interior of my printer, which has been smearing ink on printouts. Emboldened by a couple of youtube videos I got in there with tissues and paper towel and alcohol and sopped up the excess ink and cleaned the bottom of the print head.