When I was a teenager living in New York some 20 years ago, I bought a tiny introduction to Zen Buddhism from a bookstore in midtown Manhattan. A $1 clearance-sale copy, it was so small that I could slip it into my back pocket.

But that little book changed my life.

Following its instructions, I began sitting in a quiet spot every day to breathe. Just that: Breathe. With my mind's eye, I "watched" the air travel through my nostrils and into my lungs. The air seemed like a golden tide, arriving and departing in soothing waves.