04/29/2008 05:12 am ET | Updated Nov 17, 2011

Mental Ecology: The Art Of List-Making

In honor of Earth Day, let's look at how to use our natural mental resources more effectively.

My systems are set up and maintained with a standard of thinking as little as possible. That way I can use my mind to think ABOUT my work, instead of thinking OF it.

It looks to the casual observer just the opposite. The perception is often something like, "You have so many lists! Isn't it confusing and a lot of work to remember where to put things and to maintain all that?" They think their mind has better things to do.

That might be true, if I had arbitrarily created all that at one time. But it didn't happen that way.

It took years of experimentation to discover that putting anything but what had to happen that particular day on a calendar caused me to have to think about the page every time I looked at it. "What has to happen today, and what could possibly slide to tomorrow?"

I used to have all of my at-computer actions on one "At Computer" list. After many occasions when I found myself sitting on a plane and having to decipher which ones I could do, and which ones I couldn't (because they required an on-line connection), I spun out a separate "On Line" action list, which I didn't have to bother with on a plane, and which removed the mental static from the "At Computer" list.

Here's an example for anyone who still has a few or a few thousand emails stagnating in the Inbox. Reading an email, then closing it and leaving it in the Inbox because it might not seem as important as other emails at the moment creates double reading, double thinking, and double decision-making. Not to mention the nagging it creates in the psyche in the meantime. That's a waste of mental energy.

My mind has better things to do.

You can find out more about David Allen and GTD at

The David Allen Company is a professional training, coaching, and management consulting organization, based in Ojai, California. Its purpose is to enhance performance and improve the quality of life by providing the world's best information, education, and products in the fields of personal productivity and work/life balance.