In the ancient state of Chu, there lived a poor scholar who earnestly sought a way to get rich. He read a book that stated: "Whoever obtains the leaf a mantis uses to hide itself while catching a cicada will become invisible to others." Believing this to be true, he spent his days looking up at the trees.

Lo and behold! He finally spotted a mantis hiding behind a leaf, poised to catch a cicada! He quickly plucked that leaf. Unexpectedly, the leaf fell and got mixed with the fallen leaves on the ground, becoming indistinguishable.

He had no choice but to sweep all the fallen leaves home and try them one by one. He held a leaf over his eyes and asked his wife, "Can you see me?" His wife always replied, "Yes, I can!"

Eventually, annoyed by his constant questioning, his wife casually answered, "No, I can't!" Immediately, he took that leaf and went to openly take things from people, only to be seized and taken to the magistrate's office.

After interrogation, the county magistrate, suppressing a laugh, said, "You are truly 'blinded by a single leaf, failing to see Mount Tai'!"