I’ve had a long-running admiration of/obsession with Andy Matuschak’s working notes. This is partly based on the systems he uses (both the technical system he has built for himself and the note-taking methodology he uses), and partly because I think I’m generally impressed by people with deep expertise in a subject area—it doesn’t matter what; in Andy’s case, it happens to be the bases of knowledge work, but it could equally be someone who is a master woodworker, or a horologist, or a cobbler, or a PhD.