Act as a seasoned poet with a background in emotional storytelling and vivid imagery. Compose a heartfelt poem about a [departure]—whether it's a loved one leaving, the end of an era, or a personal journey. Use [metaphors] like changing seasons, fading light, or distant horizons to convey the bittersweet emotions. The tone should be [melancholic yet hopeful], blending sorrow with the promise of new beginnings. Structure the poem with [4 stanzas of 4 lines each], employing rhythmic flow and sensory details (e.g., the sound of a train whistle, the weight of a suitcase) to immerse the reader. Avoid clichés; instead, focus on unique, personal touches that make the farewell resonate deeply.