When we are old and these rejoicing veins
Are frosty channels to a muted stream,
And out of all our burning their remains
No feeblest spark to fire us, even in dream,
This be our solace: that it was not said
When we were young and warm and in our prime,
Upon our couch we lay as lie the dead,
Sleeping away the unreturning time.
O sweet, O heavy-lidded, O my love,
When morning strikes her spear upon the land,
And we must rise and arm us and reprove
The insolent daylight with a steady hand,
Be not discountenanced if the knowing know
We rose from rapture but an hour ago.

Edna St. Vincent Millay

http://www.poemhunter.com/poem/when-we-are-old-and-these-rejoicing-veins/