Lots of intriguing stuff here, but even though it was written fairly recently (2009?), it felt a bit dated. I was disappointed with the hackneyed warnings against the dangers of carbon emissions, global warming, etc. Ditto for the dire predictions that our world will end in the next century, with only a few people living in Antarctica, learning the survival skills of our ancestors, living off the land.... Um. Maybe? I was hoping for more personal spiritual epiphanies to round out the book, or perhaps a nostalgic reminiscence on how the author's life has been altered by this rather profound pilgrimage he took in the 80's.