数学不是一项观赏性运动;要理解它,必须积极参与其中。
The key is to keep improving, to keep working hard.
The task of art today is to bring chaos into order.
Generally speaking, envy, resentment, and self-pity are disastrous modes of thoughts.Self-pity gets fairly close to paranoia, and paranoia is one of the very hardest things to reverse.