Though I am an old man 
With my bones very brittle, 
Though I am a poor old man 
Worth very little, 
Yet I suck at my long pipe 
At peace in the sun, 
I do not fret nor much regret 
That my work is done. 
 
If I were a young man 
With my bones full of marrow, 
Oh, if I were a bold young man 
Straight as an arrow, 
And if I had the same years 
To live once again, 
I would not change their simple range 
Of laughter and pain. 
 
If I were a young man 
And young was my Lily, 
A smart girl, a bold young man, 
Both of us silly. 
And though from time before I knew 
She'd stab me with pain, 
Though well I knew she'd not be true, 
I'd love her again. 
 
If I were a young man 
With a brisk, healthy body, 
Oh, if I were a bold young man 
With love of rum toddy, 
Though I knew that I was spiting 
My old age with pain, 
My happy lip would touch and sip 
Again and again. 
 
If I were a young man 
With my bones full of marrow, 
Oh, if I were a bold young man 
Straight as an arrow, 
I'd store up no virtue 
For Heaven's distant plain, 
I'd live at ease as I did please 
And sin once again.
Robert Graves
http://www.poemhunter.com/poem/brittle-bones-2/