Star Wars fans come in all shapes and sizes. Sometimes they look like scruffy, twenty-something writers from a small island on the arse-end of the world. Other times they look like besuited, seventy-year-old billionaire fund managers from the American mid-west. David Booth is co-founder of Dimensional Fund Advisors, which manages about $445 billion of investor cash. I didn’t get to ask him to weigh in on the Han vs Greedo controversy, but our conversation was still among the most life-changing I’ve ever had.