For ages hence, or for many years now, the narrator wonders what would have happened if he had taken the other road. In fact, he tarried where the two roads diverged. He stared down both roads. Why is the narrator hesitant and unsure of which road to take?
No doubt, this poem is a "what if" type of poem. Notice the title is about the road the narrator did not take. He is writing about the road he did not take. He is wondering what would have happened in his life if had taken the other road.
By the last stanza, the reader is speculative about the author's "sigh." Is he sighing in a relieved sigh or is he saddened by the fact that he did not take the other road?
I shall be telling this with a sigh
Somewhere ages and ages hence:
It is true that the narrator desired to take both roads. He is torn between the two roads:
And both that morning equally lay
In leaves no step had trodden black.
Oh, I kept the first for another day!
Yet knowing how way leads on to way,
I doubted if I should ever come back.
Sadly, the reader could not take both roads. The road one takes in life determines so much about one's life. Did the narrator take the right road? Would the other road have made a difference in his life?Ultimately, the narrator "sighs" in reflection, but claims that the road he took has made the difference.
Truly, by the end of the poem, the reader gathers that the poet is mostly satisfied with his choice of the two roads. He admits that he took the road that less people traveled and that has made all the difference:
Two roads diverged in a wood, and I--
I took the one less traveled by,
And that has made all the difference.
In life, often the road less traveled by is the best road. It is difficult to take a road less traveled by for the grass is much taller. It is easy to walk where others have already tread down the grass. Though the less traveled by road has difficuly in passage, it is the road in which the traveler will not be persuaded to follow the crowd. Obviously, the narrator knew which road to take all along. That does not mean we will not be tempted in life.