Sums up perfectly for me why it has taken so long to get GTD going. It took me ages to get and understand the organising of my next action list, then once going on that I focussed on a complete projects list, then on backlog, then focussed on organising my project support, then focussed on getting my paper inbox to zero, now focussing on getting my email inbox to zero... I've had to get each one going and memorised before able to focus on the next one. You need to be able to remember the earlier bits off by heart before moving on to the next challenge.