Ask HN: What book that you read in 2015 significantly affected how you think?

Mine (they were read in this order, and I have left off many that weren't as good): Zero to One, Poor Charlie's Almanack, Snowball, The Outsiders (8 CEOs, not the fiction novel), Sapiens, Principles by Ray Dalio, Overcoming the 5 Dysfunctions of a Team, The Road to Character