The woods were my Ritalin. Nature calmed me, focused me, and yet excited my senses.

There's a generation now that didn't grow up in nature. Some of these adults are parents and they know that nature is good for their kids but they don't know where to start.

What if more and more parents, grandparents and kids around the country band together to create outdoor adventure clubs, family nature networks, family outdoor clubs, or green gyms? What if this approach becomes the norm in every community?

In medieval times, if someone displayed the symptoms we now identify as boredom, that person was thought to be committing something called acedia, a 'dangerous form of spiritual alienation' -- a devaluing of the world and its creator.

The Centers for Disease Control (CDC) reports that the number of overweight adult Americans increased over 60 percent between 1991 and 2000. According to CDC data, the U.S. population of overweight children between ages two and five increased by almost 36 percent from 1989 to 1999.

Now, my tree-climbing days long behind me, I often think about the lasting value of those early, deliciously idle days. I have come to appreciate the long view afforded by those treetops. The woods were my Ritalin. Nature calmed me, focused me, and yet excited my senses.

This seems clear enough: When truly present in nature, we do use all our senses at the same time, which is the optimum state of learning.