What is the meaning of the poem "Don't walk gently into that fine night" quoted by the movie Interstellar?

The meaning of this poem is to tell people not to give up hope of life.

This is a poem written by Dylan Marles Thomas to his father. At that time, his father was dying, had given up the hope of living and was ready to leave this world quietly. Dylan Marles Thomas has a deep affection for his father. His literary career is directly related to his father, who used to be an English literature teacher. The poet hopes that his poems can arouse his father's fighting spirit to overcome death and never give up any hope of living.

In poetry, "good night" and "lights out" are metaphors of death. In a fierce tone, the poet advised people not to be at the mercy of fate, not to give up hope of life, and never to "walk gently into that beautiful night"

In the following paragraphs, the poet divides people into four categories: the wise, the good, the savage and the grave man. Wise men are those who leave their mark on history; Good people are those who are kind and talented but weak and lack mobility; Crazy people are those who pursue unrealistic goals but keep chasing them; A serious person is one who is dying, but still full of longing for life.

The poet tells us that no matter what kind of person you are demoted to, you can't give in to fate, let alone "walk quietly into that beautiful night."