W.B. Yeats (1885-1939)
“The Unavoidable Poet’ again.
This is early Yeats. It's not an infallible test, since he never lost the art of it, but you can often tell by those long vowel sounds that set up the melodic line and make the poem sing itself. It’s not surprising this poem this has been set to music and sung.
Aengus Og, in Irish Mythology, is the god associated with youth. In one version of his story, Aengus is cursed to follow his lover, who is changed from one thing to another. Yeats has taken the story, but this is now as much persistence as it is the impossibility of his love for Maud Gonne.
Anyone who claims Aengus is stalking the girl is not paying close attention to the verbs.