记忆是复杂的东西，是真相的亲戚，但不是它的双胞胎。
"Memory is a complicated thing, a relative to truth, but not its twin."
We teach a subject not to produce little living libraries on that subject, but rather to get a student to think mathematically for himself.
Quality is not a position; it is a practice.
不管战略多美妙，偶尔看看结果如何很重要。