In ancient times, there was a man who wanted to build a mountain nine ren (eight feet = one ren) high. He piled it year after year, no matter the severe cold or scorching heat, he worked tirelessly to dig soil from a distance, pick up the soil, and pile it on the mountain. Finally one day, he was about to finish it. This day was the same as usual. I got up as soon as the rooster crowed and started working, one basket after another. Seeing that the mountain was almost nine feet high, there was only one basket of soil left. But when his stomach growled and it began to snow again, he thought there was only a basket of soil, so he went home. From then on, he always thought that he only had one basket of soil and was lazy, so he did not pile up this basket of soil until his death. In the end, the nine-foot-high mountain with only one basket of soil was still not completed (it was a nine-foot-high mountain, but he failed in the end) .