Gödel, Escher, Bach by Douglas Hofsteder. Barely needs any introduction here, but the depth of thought is just staggering. Lights Out in Wonderland by D.B.C. Pierre. A wonderful story with a few incidental observations about modern society. The Grapes of Wrath by John Steinbeck. Sure, you can read about people who've made everything, but what about people who lose everything. Absolutely everything. Shattering, tragic fiction.
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