Ever remember to do something when it's the last thing you could possibly be doing? Like, you're at the barber shop having your hair cut, and your to-do list starts coming out of the woodwork. Like how you've been meaning to clean out the closets, or shine up the chrome on your car, etc. Why is your subconscious reminding you to do something when it's the last thing you could possibly do? Why don't you remember to do this when it's convenient?
This, and more, is covered in Getting Things Done: The Art of Stress-Free Productivity. In this and his other books David Allen has been exploring the subconscious processes that interfere with getting things done, and he offers practices to help one better manage the tasks we have in life.
The way he puts it, the source of this is the operation of human consciousness. How many items can you hold in short term memory? Psychologists have studied this in every way, and shown it's possible to hold 5-7 items in short term memory. This means the vast majority of things we are remembering are stored in long term memory, and long term memories surface when the triggered, not necessarily when they're convenient.
For example, sitting in a barber chair is a very relaxing place, and when the mind relaxes the pending items in your mind will tend to surface. Meditators through the millennia have known this, they call this the monkey mind. When meditating it's widely recognized a flood of ideas will surface, and it is part of meditation to learn how to focus on something even with the distracting thoughts surfacing from the subconscious. The same process occurs in the rest of our lives, with the subconscious surfacing ideas and thoughts at a time and place of its choosing.
In Getting Things Done: The Art of Stress-Free Productivity the focus is on practical issues of more efficiently recording ones to-do list. The idea is to help your subconscious relax by purposely recording all the to-do items you've entrusted to the subconscious. By recording all your to-do items your subconscious doesn't have to work to keep reminding you of these things, and instead you can trust the system you build that holds the reminders.
It sounds great, but in the back of my mind I'm wondering, what happens if the reminder system is lost or stolen? For example if you have a "smart phone" which you've used to hold all your to-do items, what happens if the phone is left in your pants and goes into the laundry? Or if it's stolen or lost? Hopefully you kept the phone backed up onto a computer, but since when does anybody make backups? And what if the backup of your phone contents cannot be copied into the replacement phone (because the phones are incompatible)?