The world is changing, people are changing, everything is changing, the only constant is that everything is changing, and everything will change within a period of time.

So the unchanging fact is that everything is changing, and what remains unchanged is time. Time will only run forward, not reverse, and this is also unchanging.

Quotation is a Chinese word, pinyin is míng yán. Its basic meaning is a very famous saying. Famous words generally refer to what celebrities say. From Liu Yiqing's "Shishuo Xinyu·Yu", Ouyang Xiu's "Guitian Lu", etc.