The poem consists of one elaborate metaphor. The speaker is inside the metaphor until the last stanza. The metaphor is relatively simple. The speaker once came to a fork in the road and had to choose one road or the other without knowing where either one would take him. There were no real roads or trees. The roads in the metaphor represent life choices. The speaker, perhaps Robert Frost himself, reached a point in life (as many poets and other artistic people do) where he had to choose between utilizing his talents to make a good living in some secure profession or accept a bare existence and be able to devote all his time to his art. Frost chose the life of a New England subsistence farmer, as is evident in many of his poems. In the final stanza of "The Road Not Taken" he reveals that he has some regrets about not choosing the other "road," which would have probably led to prosperity and an entirely different lifestyle for a man with his intelligence and talent.
To write prose and verse, to hammer out little tunes on the piano, and to draw and paint, are instinctive with a great many young persons. It is a form of play, due merely to the exuberance of their years, and is no more significant than a child’s building of a castle on the sands....The point I want to make is that this facility is, if not universal, so common that one can draw no conclusions from it. Youth is the inspiration. One of the tragedies of the arts is the spectacle of the vast number of persons who have been misled by this passing fertility to devote their lives to the effort of creation. Their invention deserts them as they grow older, and they are faced with the long years before them in which, unfitted by now for a more humdrum calling, they harass their wearied brain to beat out material it is incapable of giving them. They are lucky when, with what bitterness we know, they can make a living in ways, like journalism or teaching, that are allied to the arts.
Somerset Maugham, The Summing Up
Vast numbers of young persons have been misled by this passing fertility to devote their lives to the effort of creation. Frost had no way of knowing whether he could achieve recognition as a poet. In fact, he probably had no idea whether he really possessed the talent he sometimes felt he had. That is why in his metaphor he says that he stood in one spot and looked down both roads for such a long time. It was undoubtedly the biggest decision he ever had to make in his life. For Frost it was the right decision. He became a famous poet, and his inspiration did not dry up. He was honored by being asked to read one of his poems at President John F. Kennedy’s inauguration in 1961. He once confided in a young correspondent:
No wonder you were a little puzzled over the end of my Road Not Taken. It was my rather private jest at the expense of those who might think I would yet live to be sorry for the way I had taken in life. I suppose I was gently teasing them….