What kind of thoughts and feelings does the poem Ma Shi express?

Ma Shi is a set of five-character quatrains written by Li He, a poet in the middle Tang Dynasty. By chanting, praising or lamenting the fate of the horse, it shows the feelings and resentment of genius, lofty aspirations and people with lofty aspirations. It seems to write about horses, but in fact, it expresses the poet's talent through horses, which is not appreciated by the rulers, but is eager to display their ambitions and make contributions to the country.