S' i' avessi creduto.

Had I but earlier known that from the eyes
Of that bright soul that fires me like the sun,
I might have drawn new strength my race to run,
Burning as burns the phoenix ere it dies;
Even as the stag or lynx or leopard flies
To seek his pleasure and his pain to shun,
Each word, each smile of her would I have won,
Flying where now sad age all flight denies.
Yet why complain? For even now I find
In that glad angel's face, so full of rest,
Health and content, heart's ease and peace of mind
Perchance I might have been less simply blest,
Finding her sooner: if 'tis age alone
That lets me soar with her to seek God's throne.

Michelangelo Buonarroti

http://www.poemhunter.com/poem/l-in-love-s-own-time/