Love Song Confusion

This poem alone made little sense to me during class. Without someone skilled in the poetry or literature fields I do not understand how anyone could make sense out of the various allusions. In class you said that the main task of the poet is to get their message across to the reader, but because of the difficulty most normal people would have in comprehending I can see that the poet's reader demographic has to be very select and upper class. I wonder how the poet can sit and write something so complex and expect his readers to regard it well when it takes so much analysis and time to get a small jest past the poem's surface.