Another semi-lapsed student here: I keep reading lectures and comments, but due to work and family commitments I stopped doing exercises and puzzles a few weeks ago - around the time of Kan extensions - with the natural consequences for my understanding of the material.

I join in the thanks to John for all his work - and thanks also to the more active students in the forum!

I think the course is great and I plan to go over the material more carefully when I have more time (btw, yes, having it all collated in a single PDF file, if not also a properly edited printed book, would be extremely useful!)