We sometimes let opportunities slip through our grasp, forgetting that our lives are over in the blink of an eye. I was recently talking to a friend about hindsight. Have you ever thought, “If I could go back in time, I’d do that differently,” or “If I knew then what I know now”? Such thought experiments can leave us either ready for a more thoughtful future or melancholic about our past. Charles Gleyre’s painting “Lost Illusions” (also called “The Evening”) illustrates the melancholy and thoughtfulness that can derive from missed opportunities. Charles Gleyre and ‘Lost Illusions’ Gleyre was a 19th-century Swiss artist who painted mostly in France. He used his academic training to produce romantic paintings, one of which was his most famous, “Lost Illusions.” “Lost Illusions” was a painting based on a hallucination that Gleyre experienced as a young man on the bank on the Nile during his travels …