The Years like great black oxen tread the world,
And God the herdsman goads them on behind,
And I am broken by their passing feet.
~ W.B. Yeats, "The Countess Cathleen"
He wrote this when he was in his mid-twenties. How much more he would be feeling it 4 decades later. Or maybe not? Maybe age is most oppressive when we are young & don't know how much we'll get.