Why does the author repeatedly recite "I don't know which direction the wind blows" in the poem?

I don't know which direction the wind is blowing.

I am wandering in the clear waves in my dream.

I don't know which direction the wind is blowing.

I was dreaming, and she fascinated me.

I don't know which direction the wind is blowing.

I am sweet in the dream, and I am the glory in the dream.

I don't know which direction the wind is blowing.

I dreamed of her infidelity and my sadness.

I don't know which direction the wind is blowing.

I was dreaming, and she fascinated me.

I don't know which direction the wind is blowing.

I am sweet in the dream, and I am the glory in the dream.

I don't know which direction the wind is blowing.

There are faint sad memories, confused and helpless. . .