铁杵磨针 — “To grind an iron pestle into a needle”

The famous Tang Dynasty poet Li Bai disliked studying when he was young. He often skipped school to wander the streets.

One day, Li Bai skipped school again and roamed around outside the city. The warm sunshine, cheerful birds, and swaying flowers made Li Bai exclaim, "What a wonderful day! How boring it would be to spend all day reading indoors!"

As he walked, he saw an old woman with white hair sitting by the entrance of a dilapidated hut, grinding an iron pestle as thick as a stick. Li Bai approached her and asked, "Granny, what are you doing?"

The old woman looked up, smiled at Li Bai, and then lowered her head to continue grinding. "I want to grind this iron pestle into an embroidery needle."

"An embroidery needle?" Li Bai asked again, "Is it for sewing clothes?" "Of course!" "But the iron pestle is so thick; when will it ever be ground into a fine embroidery needle?" The old woman retorted, "If dripping water can wear through stone, and the Foolish Old Man could move mountains, why can't an iron pestle be ground into an embroidery needle?" "But you are already so old?" "As long as I put in more effort than others, there is nothing that cannot be accomplished."

The old woman's words made Li Bai feel very ashamed. After returning home, he never skipped school again. He studied diligently every day and eventually became the legendary 'Immortal Poet' whose fame echoed through the ages.