Ask HN: Which non-technology book has influenced you the most and why?
"Zen and the Art of Motorcycle Maintenance" by Robert Pirsig.  While it's also a tale of travel and self-exploration (the rediscovery of identity after a nervous breakdown and shock therapy), mostly the book is about thinking.  I was a different person after identifying with the narrator who also lived in the mind, and asked questions about basic concepts like 'quality', or qualia of events, objects, roles, and the subjective/objective values they embody or we impart on them.  A watershed book for me.