Few of us consider ourselves philosophers. “Philosophy” usually conjures images of dense textbooks and academic quibbling with no application to real life. It’s fun for professors, perhaps, but a waste of time for the rest of us. I felt this way for decades. Then, in 2004, I found the work of Lucius Annaeus Seneca, better known as Seneca the Younger or simply “Seneca.” Born circa 4 BC in present day Spain and raised in Rome, Seneca was simultaneously an esteemed playwright, one of the wealthiest people in Rome, a famous statesman, and an advisor to the emperor. He had to negotiate, persuade, and strategize his way through life. Far from spouting philosophy from the safety of an ivory tower, he had to constantly deal with uncooperative, powerful human beings and faced disaster, exile, and death head on. Seneca took risks and did big things. His primary philosophy, Stoicism, was founded around 300 BC in Athens and can be thought of as an operating system for thriving in high-stress environments. At its core, it teaches you how to separate what you can control from what you cannot, and it trains you to focus exclusively on the former. Seneca’s Moral Letters to Lucilius—a distillation of his lessons learned—changed my life and continues to do so today.