What does "no joy, no sorrow, no sorrow, no joy" mean?

The general idea of the sentence "No joy, no sorrow, no sorrow, no joy" is that nothing deserves my joy and nothing makes me sad.

Appreciation of this word: Life is alive, and all kinds of events encountered can be treated with a peaceful attitude of not being too happy with good things and not being too sad with misfortune. This is a kind of consciousness after vicissitudes of life. In a mutual way.

Sentence: If there is an afterlife, I would like to turn into dust!

if there is an afterlife, I would like to become a big tree!

if there is an afterlife, I would like to turn into a stone!

no joy, no sorrow, no sorrow, no joy.