How often to update lists
When I started with GtD, I thought these lists were wonderful and I was obsessed with keeping them up-to-date continuously. I spent too much time on these lists and then silly things started to happen, e.g., I would make a call and leave a message, change my NA into a Wf, go and file the related paper somewhere, and while I was doing that or within minutes I would get the call back, or I would get the callback while I was working on something else and then have to re-orient myself to what had now become an interruption.
One day, I actually internalized something in the Weekly Review chapter - one of the first things to Do in Weekly Review is to update your lists for completes that haven't yet been recorded. Then I realized that if you have a periodic routine for updating your lists, then you don't have to do it in real time. The question was "how often?" and I decided that daily seemed right. So I now keep a daily journal and things like LM just get noted and the paper kept handy on my desk tucked into the journal or in a Today folder, and when I get that callback, it doesn't seem like so much of an interruption or a hassle any more. I just update my lists at the end of the day, if there is anything for that matter that needs to be noted.
In other words, if I got your bank letter in my mail and made the call immediately and they called me back same day, I may never write anything on my lists - it's a Do Now item that will still be Do Now when the callback comes. If I don't get the callback by the end of the day, then I will Process my journal note as normal. If you turn this incident around and, say, you were working on something and the phone rang or someone walked into your office, you wouldn't write an NA for the work and file away the papers before you dealt with the interruption. You would leave your stuff on your desk ready to go back to it when the interruption is over. My daily journal serves the same purpose - it minimizes the disruption caused by interruptions in the flow of work.
The only time you need a complete inventory is when you are reviewing the complete inventory. Continuously updating the lists and files in real time seems to me to be an enormous waste of time.
Andrew