First personal knowledge management is not a new field, it was just called "note taking" before.
Second the place where you really need to manage knowledge is at your job. Using a system that requires discipline at work is usually a bad idea as most people are not disciplined. Also at work information is spread around different applications which makes sorting all information about everything into folders difficult
Finally if that method works for the author then good, but I also have also method that works for me which is : try to take notes of almost nothing