"How do you do it?" People frequently ask me, shaking their heads incredulously. They said it when we cruised for almost ten years on a 46-foot sailboat, and they say it now whilst we keep The Light on a two-acre uninhabited island for five months.

Truth be told it's not that different from the every day lives of most other people. I have a theory that we all live in two bubbles-a small personal sphere and a larger worldly sphere. When we are personally connected to those around us, we are aware of a space about the size of a dinner table. We can hear each other talk. We can read each other's...