The teacher pretended that algebra was a perfectly natural affair, to be taken for granted, whereas I didn't even know what numbers were. Mathematics classes became sheer terror and torture to me. I was so intimidated by my incomprehension that I did not dare to ask any questions.
老师声称代数是完美而自然的、我们应无条件地接受它，而我甚至不能理解什么是数。对我来说数学课完全就是恐怖和折磨。我完全不理解代数，这使我胆怯得不敢问任何问题。
——杜先生晚年在香港，先生为中国抗战.赈灾慈善做出巨大贡献，晚年依旧气度过人，毁掉所有欠条。
所谓的天才是不断地承受痛楚。