Noah Smith on the two things that killed the hippie era, the econ distinction between risk and ambiguity, and why the real entrepreneurs left the internet in 2016: "Two things happened. Number one is Facebook, the IPO. It made so much money. Everyone was like, money. And then the financial crisis happened. If you were an upper middle class striver in 2006, you went to become an investment banker. In 2012, you went to do a tech startup" "When Bill Gates dropped out of college to do Microsoft,…