Always look at what you have left. Never look at what you have lost.

The Liskov Substitution Principle is a fundamental concept in object-oriented programming, stating that objects of a superclass should be replaceable with objects of a subclass without affecting the correctness of the program.

真相很少是纯粹的，也绝不简单。

我们都是进化之树上的叶子。

"The colony is the place where the project of a new humanity is to be tested, where the dream of a world without borders is to be realized, where the dream of a world without races is to be realized, where the dream of a world without nations is to be realized, where the dream of a world without classes is to be realized, where the dream of a world without genders is to be realized, where the dream of a world without religions is to be realized, where the dream of a world without money is to be realized."