In "The Difficult Path," what is Li Po's poem "The Difficult Path" about, and why is the poem significant to the story?

The lines Lingsi reads in the story concern the ocean, reading the winds and the waves across the vastness of the sea until one day he finally reaches the distant shores. As Lingsi's tutor explains, Li Po writes of endless hardships, but of also trying always to maintain a valiant spirit in the face of these hardships. The ideas in the poem become both literally and symbolically true for Lingsi in the end of the story when she joins a pirate crew and uses the sea as her own means of escape from hardship.