Things fall apart... such as my memory of where certain quotes come from...

I first encountered these lines as the title to the great break-out album by The Roots. "You Got Me", originally written about Jill Scott but sung by Erykah Badu, even contains the lines, about a relationship, 'things fall apart'. We used to sing this song in my freshman dorm room...
But I new it was from somewhere: the Nigerian author Chinua Achebe's English-language novel from the fifties of the same title. But it goes back further - William Butler Yeats, in a poem entitled The Second Coming.
So they're Yeats' lines. Only the thread then lead me back to another great whom I cannot escape, Percy Bysshe Shelley. From his Prometheus Unbound:
The good want power, but to weep barren tears.
The powerful goodness want: worse need for them.
The wise want love, and those who love want wisdom;
And all best things are thus confused to ill.
We, human creatures, always want what we don't have. Knowing this, I continue wanting.