My approach to GTD and PKM

Justin Duke writes his experience in using Things and GTD, and his suspicion of PKM.

Some observations of Justin's task setup in Things are:

• Only 4 areas, but quite a few projects in each area (and projects taking the GTD definition)
• Prefixes project names with 'x' for blocked or delegated tasks
• Prefixes project names with '∞' for 'unfinishable' tasks

I appreciate his link to Andy Matuschak's note on writing about note-taking:

most people who write about note-taking ... aren’t applying their notes to some exogenous creative problem: their primary creative work is writing about productivity

This connects to Justin's side note about personal note-taking:

("What about the stuff that you don't need to share with anything else?", one might ask. I posit to you: this information probably does not need to be recorded, and you probably have better things to do with your time.)

I don't quite agree with this as I find it helpful to take notes to augment my own patchy memory, but on the other hand, I write plenty of short notes which I never look at again. However, can I predict ahead of time which notes these are?