"Books are the maps that guide us through life."

相位裕度是系统在变得不稳定之前可以容忍的程度的度量。

Flow is being completely involved in an activity for its own sake. The ego falls away. Time flies. Every action, movement, and thought follows inevitably from the previous one, like playing jazz. Your whole being is involved, and you're using your skills to the utmost.