Some people have called this a wonderfully written poem, and others have called it one of the most misconstrued work of literature in the history of writing. I have seen and heard many people interpret this entire poem by the last few lines, saying how it is a poem that tells the reader to stray from the crowd, to go the other way, and to be different. Judging a poem by the last lines is like judging someone by the condition of their toenails, it says something about the person, but not much.
It is generally good to begin at the beginning, so that is where I shall begin this discourse. I can close my eyes and see the scene that Frost is trying to draw. It is autumn, and it is a rather sunny day. The speaker had been taking a walk in the woods when suddenly he is confronted with a diverging path. They both looked about the same, with grass that was slightly trodden and a certain amount of undergrowth that obscured the destination of the path. Both paths have never been traveled by anyone else. Both paths seem to beckon the speaker to take them and move forward through the forest. The speaker stands there, looks at one path for as far as he can see, and almost on a whim decides on taking the path opposite of the one he first viewed. In the beginning the speaker wishes that he could take both paths at the same time, but he knows there is no possibility in that. The speaker then states, upon beginning his trek down his decided path, that he really would like to come back someday and take the other path, but that will not happen because the speaker will be too far down the other path.
Could this be a metaphor for life? Sure, why not? In life you will suddenly be struck with a decision. It could range in importance from when to take the dog on a walk to buying that first house even though you may not have enough money to afford it with help from the bank. Regardless, there is a decision to be made, and there are only two options, one or the other. You can weigh the options, but in the end the consequences are relatively equal, but regardless you are somewhat unsure because you have never had to make a decision like this before. It almost comes down to a coin flip when suddenly, almost on a whim, you decide to go a certain course in your life. You make the decision, and you will never be able to go back and change it (unless someone perfects time travel, but I will save quantum-physics for another day.)
So what of that last stanza that everyone seems to be so infatuated with? What about those toenails? The meaning of things is quite simple in my eyes. The speaker made his decision and stuck to it. Sometimes though, he pondered back to that little space in the woods where there were two paths. He remembered taking one, but he wondered what life would've been like if he had taken the other path.
That is all well and good, but in the end, what did make all the difference? Simple, the fact that he chose one path and not the other. Life would've been different had the speaker taken the other path, but he didn't so life became the way it was. What about "the one less traveled by"? Neither of them were less traveled than the other, they were both worn about the same "in leaves that no step had trodden black." However, they were both less traveled by him because this was the first time the speaker had come upon these paths. That is why they are less traveled by, not because many people had taken one path and not the other, but because he had never even seen either of these paths before.
That makes for a "slight" misinterpretation on the public's part, but that is not the end of this story. Two key pieces of information work together to sell the overall meaning of the poem, two pieces that the public has practically ignored for one reason or another. Firstly, the title of the poem, "The Road Not Taken," and secondly, the fact that the speaker says the entire last stanza "with a sigh." These two work together to show that the speaker is dissatisfied with the decision he made. He is unhappy that he took the path that he did. The speaker longs to go back and take the other path, but he didn't. Thus, the difference was made, and life was probably much less pleasant than it could've been. The speaker yearns to go back and take "The Road Not Taken," but he made is decision, and father time will not let him go back and go the other way.
Funny how once you read the whole poem you realize that this is not an inspirational piece about why you should be different from everyone else. Rather, it is a brief tale of what one man did in his earlier days, how little good it did him, and how he wishes he could go back and do it all over again. Yes, one's toenails may be bright, clean, and well kept, but you will not know about the rest of the person until you actually look at him.
Take one step back and read some good poetry.
If you have low expectations, go here and be happy.