This encapsulates the central Stoic insight about emotional disturbance - the problem is not external events but our judgments about them. Two people can experience the same situation and have completely different emotional responses based on their interpretations, expectations, and beliefs. Rain ruins one person's day while delighting another; criticism devastates one person while motivating another; setbacks crush one person while energizing another. The liberating implication is that we have more control over our emotional experience than we might think - by changing our perspective, we can change our feelings and responses without waiting for external circumstances to change.