Ryan Holiday is an American author, entrepreneur, and marketer. He is best known for his books The Obstacle Is the Way, Ego Is the Enemy, and Stillness Is the Key. He is also the founder of the marketing firm Brass Check and the media company Creative Strategies. Holiday began his career as a media strategist and consultant for American Apparel, where he worked for three years. He then went on to become the director of marketing for the book publisher, Penguin Books. After leaving Penguin, he founded his own marketing firm, Brass Check, which has worked with clients such as Google, TASER, and Complex. Holiday has written several books, including The Obstacle Is the Way, Ego Is the Enemy, and Stillness Is the Key. His books focus on the idea of stoicism, which is the belief that one should focus on what is within their control and accept what is outside of their control. He has also written for publications such as The New York Times, The Wall Street Journal, and Forbes. In addition to his writing and marketing work, Holiday is also a public speaker and has given talks at places such as Google, Harvard, and the United Nations. He is also the host of the podcast The Daily Stoic, which focuses on the teachings of stoicism.