Step 1: The nature of beauty.
The poet states that beauty brings joy that never ends. Unlike temporary pleasures, its influence does not diminish with time.
Step 2: Emotional and spiritual effect.
A beautiful thing continues to inspire, soothe, and refresh the human mind and soul. It creates an eternal impact by removing sadness, providing peace, and offering hope in times of despair.
Step 3: Conclusion.
Hence, beauty is called a joy forever because its charm, value, and influence remain immortal, filling human life with constant happiness.