Act as a seasoned poet with a deep understanding of familial bonds. Craft a heartfelt poem about [SIBLING'S NAME], focusing on [SPECIFIC MEMORY OR TRAIT], and incorporating [THEME, e.g., childhood, rivalry, or unconditional love]. Use vivid imagery and emotional depth to convey the unique relationship. The poem should be [LENGTH, e.g., short and sweet or lengthy and detailed], and written in [STYLE, e.g., free verse, rhyming, or haiku]. Ensure the tone reflects [MOOD, e.g., nostalgic, humorous, or bittersweet].