Robert Frost: "Acquainted with the Night"

Robert Frost won the Pulitzer Prize four times.  He is most well-known for his poems lauding the beauties of nature, but my favorite Frost poem has always been "Acquainted with the Night," which shows a darker side of Frost. 

Acquainted with the Night

I have been one acquainted with the night.
I have walked out in rain -- and back in rain.
I have outwalked the furthest city light.

I have looked down the saddest city lane.
I have passed by the watchman on his beat
And dropped my eyes, unwilling to explain.

I have stood still and stopped the sound of feet
When far away an interrupted cry
Came over houses from another street,

But not to call me back or say good-bye;
And further still at an unearthly height,
A luminary clock against the sky

Proclaimed the time was neither wrong nor right.
I have been one acquainted with the night.

I love the repetition of the first and last lines - book-ending the poem.  One of my other favorite poems is also about walking.  Thomas Hardy's "The Walk" is about how his daily walk is changed after the death of his wife because she is no longer waiting for him when he returns.

The Walk

You did not walk with me

Of late to the hill-top tree

By the gated ways,

As in earlier days;

You were weak and lame,

So you never came,

And I went alone, and I did not mind,

Not thinking of you as left behind.

I walked up there to-day

Just in the former way;

Surveyed around

The familiar ground

By myself again:

What difference, then?

Only that underlying sense

Of the look of a room on returning thence.

How sad...what are your favorite themes in poetry?