Draw a young boy sitting on a rotten wooden log, with a sad expression on his face. He is beside a train track and the background should be a lush green forest. The art should be in a cartoon style, with vivid details and vibrant colors, depicting the boy's emotion. Create a sad but at the same time, lively and colorful scene.

画一个小男孩坐在一根腐烂的木头上，脸上带着悲伤的表情。他在火车轨道旁，背景应该是郁郁葱葱的绿色森林。艺术应该采用卡通风格，细节生动，色彩鲜艳，描绘男孩的情感。创造一个悲伤但同时又生动多彩的场景。