The author’s grade-three thinking is mainly shown in his ignorance when he was a child. 2.To the headmaster, the three statuettes meant love, nature and thought respectively. 3. The author was glad that the pious lady personally taught him a great truth in thinking. 4.The author thought that grade-three thinkers were numerous and mustn’t be overlooked. 5. Because of grade-two thinking, the author became separated from other people who were grade-three thinkers. 6. Grade-one thinkers are persons of reason and logic. 7. When the author grew up, he did not have the hobby of thinking any more. 8.To the author, the three statuettes meant three levels of thinking.