From Li Bai's 《
南陵别儿童入京》 (742 CE, written when Emperor Xuanzong summoned him to the capital). Closing couplet:
仰天大笑出门去,我辈岂是蓬蒿人 (Laughing up at the sky, I stride out the door - how could men like us ever be weeds of the wild?). Written at age 42 after years of obscurity, it is the quintessential Li Bai moment of swaggering self-confidence.