有这样一个民间故事：一天，某学生自以为学得差不多了，于是决定向老师辞行，老师让这个学生端来满满一盆石子，问他：“满了吗!”学生答道：“满了“”然而，老师随手端来一碗沙子，倒在石子上面，只见沙子全都顺着石子间的缝隙流了进去，没有溢出一点来。老师又问：“满了吗! There is such a folk story: one day, a student thinks that he has learned almost, and decided to go to the teacher. The teacher asked the student to come full of pebbles and asked him: ”Is it full!“ The student replied: ”Full However, the teacher readily come to a bowl of sand, fell on the stones above, I saw the sand all flow along the gap between the stones into it, did not overflow a little. The teacher asked: "full it!