It means to live in the present and cherish everything. Life is not easy, you need to cherish what you have and experience, and don't worry about things that are not worth answering.
Cherish is a Chinese word, which means to cherish while walking. "Doing" refers to the process on the road of life, and "cherishing" refers to the attitude towards the past and the need to maintain nostalgia and gratitude for people and things that have happened. From Cihai.
There is another understanding of this sentence: moreover, there is an explanation in ancient Chinese: will; Should, should be these two meanings. So this sentence can be literally understood as: cherish each other when you leave.
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The practical significance of this sentence:
1. Cherish life, bittersweet and depressing. Just cherish the people around you. The time spent with them is happy. Cherish the happiness under the heavy blow of this life.
2, don't forget to give yourself happiness and happiness, even if separated, don't forget the friendship between them. Since you have deep feelings, you should cherish the feelings between you.