Ryan Holiday is an American author who is best known for his self-help books on Stoic habits and values. His best-selling works The Daily Stoic, Courage Is Calling, and Discipline Is Destiny explain Stoic philosophy through ancient texts and real-life anecdotes. Holiday began his career working in media strategy and marketing, working as a talent agent in Beverly Hills and later becoming the director of marketing for American Apparel while still in his early twenties. He later published the memoir Trust Me, I’m Lying: Confessions of a Media Manipulator, as well as business self-help books Growth Hacker Marketing and Perennial Seller. Holiday then shifted his writing focus to repackaging Stoic philosophy for a modern audience. In addition to his books, Holiday also takes an active interest in Stoicism on his YouTube channel and podcast Daily Stoic, as well as his Instagram account @DailyPhilosopher.

In Ego Is the Enemy, Holiday draws on his personal experiences as a young professional to illustrate how egotism can be detrimental to one’s health, relationships, and career. He reveals that while he was unusually successful at a very young age, he struggled with workaholism and idolized bosses and mentors who later disappointed him.