The real mystery about the poem is why it works at all. Those opening lines are incredibly clumsy: I will arise and go now, and go to Innisfree, / And a small cabin build there, of clay and wattles made. I mean W.B. just keeps repeating himself, doesn't he? How many times exactly does he intend to go? And since we know he will build his dinky cabin why the seemingly redundant made just a few words later? But, of course, the sense of stasis is the whole point. Notice that syntactically the shed seems to get made by someone else. He hasn't gone anywhere, and he won't. And he won't build or make anything, anywhere, except in glorious vulnerable words. Though, I suppose he builds in song. Everything about those vowel sounds says sing me yearningly. (Just as a matter of interest I was quoting from memory initially when I wrote the lines above - I checked them a minute ago, then edited - and I wrote I must away incorrectly as the first three words. How much richer Yeats's phrase sounds than mine!)
It's odd, you know, to find yourself hearing a bee-loud glade in a lift in a busy school.