Seneca, a prominent Stoic philosopher, has left a lasting impact on modern thought. In his book 'Focus on What Matters,' Darius Foroux emphasizes how Seneca's Stoic philosophy encourages self-control, resilience and a balanced approach to life. Foroux highlights five key lessons from Seneca: detaching self-worth from material success, striving for financial independence, making a positive impact on others, being content with what you have, and valuing your time. These timeless principles promote self-improvement, ethical living and the pursuit of a fulfilling life in the face of life's uncertainties.