数学家的模式，就像画家或诗人的模式一样，必须是美丽的。

The most sustainable building is the one that is already built.

癌症治疗的未来在于免疫疗法。

未来的终极竞争将是用户体验的竞争。

So given a Time Turner, I would tell my 21-year-old self that personal happiness lies in knowing that life is not a check-list of acquisition or achievement. Your qualifications, your CV, are not your life, though you will meet many people of my age and older who confuse the two. Life is difficult, and complicated, and beyond anyone’s total control, and the humility to know that will enable you to survive its vicissitudes.