Well, the whole idea behind the movie is somewhat similar in theme to The Great Gatsby, where your perception of how something was or should be never meets its expectations. In American Beauty, one of the characters finds the opposite, where everything is so intensely beautiful in every moment it is too much to bear. The rest of the characters maintain the Gatsby theme. That tells you little about the actual movie, but its just a facet of the theme.
Finding such profound concepts in such insignificant things, as in the poem, reminded me of American Beauty.