Wow. This is almost stalker-esque. If you find yourself bidding on his used keyboard on ebay, seek help.
In the same way, I don't regret reading Feynman's, Lewis Carroll's, or James Joyce's letters. Thoughtful people tend to write thoughtfully, whatever the context.
Incidentally, I probably would buy Knuth's keyboard.
Also, the majority of his comments are somewhat, uh, boring when you see them all laid out. Just simple comments/replies a lot of the time really.
I would hardly call this a "giant essay", it's more like half of a Twitter feed...
Could be there's a "more" button I'm not seeing, though.