The song delivers some really powerful message about the simplicity of happiness and its ellussive nature. Every day can be beautiful if you just pay attention to all little things like a blue sky or a bird with a leaf in its mouth . Happiness can be found in little things and after all as the song says:
"What you don't have you don't need it now..."
From a literature point of view, the song relates to the famous Irish novel "Ulysses". The plot of Ulysses takes place all in one day hence the "Day" in the song title. The main character in the novel is Mr. Bloom and the opening line to the song is "The heart is a bloom" - maybe that's a clue. Also, the lyrics "You're on the road/But you've got no destination/You're in the mud/In the maze of her imagination" totally make sense: Bloom spends most of his day just wandering around Dublin with no real destination in mind. The last line of those lyrics also could refer to the end chapter of "Ulysses". In that chapter, Bloom's wife thinks about her and her husband's past, but the whole thing is in a continuous, unpunctuated stream. It's really hard to read and I can see how it could be thought of as a maze.
