William Butler Yeats (13 June 1865 – 28 January 1939 / County Dublin / Ireland)

There is an interesting contrast here with Thomas Hardy's great poem, 'I Look into my Mirror.'

I LOOK into my glass,
And view my wasting skin,
And say, 'Would God it came to pass
My heart had shrunk as thin! '

For then, I, undistrest
By hearts grown cold to me,
Could lonely wait my endless rest
With equanimity.

But Time, to make me grieve,
Part steals, lets part abide;
And shakes this fragile frame at eve
With throbbings of noontide.

Yeats laments that the heart grows old, even though one keeps the body in shape.
He still feels sexual desire, but regrets that he is unable to satisfy it in others.He in fact mourns the death of the heart, without specifying exactly where it lies.
Hardy's poem is a complete contrast.Looking into his mirror, he objectively notes the destruction wrought by age and wishes that his capacity to feel had diminished alongside with his features.
The second verse tells us that what hurts most is the falling off of affection towards him; the felt loss of love from those who mean most to him.
He notes that bodily and emotional decrepitude - the capacity to feel and care –do not go hand in hand; one dies piecemeal.
The ‘throbbings of noontide’ refers not just to memories but to this lasting capacity to feel and care.
So much in three verses, using ballad form and a simple abab rhyme scheme, is itself a definition of genius.