Stoicism is a philosophical school of thought that teaches individuals how to navigate life's challenges with resilience and a calm mind. When facing disappointment, here are some Stoic principles that may provide guidance:

1. Practice gratitude: Shift your focus from what went wrong to what is still positive in your life. Reflect on the things you're grateful for, as this can help you maintain a positive perspective and reduce the impact of disappointment.
2. See obstacles as opportunities: Stoicism encourages viewing challenges as opportunities for personal development. When faced with disappointment, consider how you can learn and grow from the experience. This shift in mindset can turn setbacks into stepping stones toward improvement.
3. Maintain inner tranquility: Stoicism teaches the importance of maintaining inner peace regardless of external circumstances. Instead of letting disappointment consume you, strive to cultivate a calm and rational mind. This can help you approach challenges with a clear and focused mindset.
4. Understand the impermanence of emotions: Stoicism highlights the transient nature of emotions. Recognize that feelings of disappointment will pass, and they don't define you. By understanding the impermanence of emotions, you can navigate through difficult times with greater resilience.
5. Reframe your perspective: Challenge negative thoughts and reframe your perspective on the situation. Consider alternative viewpoints that might lead to a more constructive and positive understanding of the disappointment.