数学的乐趣在于努力理解的过程。

练习时多流汗，战场上少流血。

The choice for mankind lies between freedom and happiness and for the great bulk of mankind, happiness is better.

命中注定。如果我真的成为了你梦的一部分，你终将会回来。

The best way to untangle a knotty tangle is not to “untie” the knots， but to keep pulling the loops apart wider and wider. Just make the mess as big， loose and open as possible. As you open up the knots they will unravel themselves. Works on cords， strings， hoses， yarns， or electronic cables.