In the closing lines of "The Road Not Taken," Frost suggests that the path he took "has made all the difference." "The Road Not Taken" comments on both the process and product of the decisions we make. In the poem, the speaker is poised between equally desirable, but ultimately incompatible courses of the good. This ancient definition of tragedy is highlighted when the speaker opens the poem suggesting that he "was sorry I could not travel both." There is little to suggest that one was the "right" choice and the other the "wrong" choice. The reality is that the fork in the road diverged both, so he must be forced to choose. There is no external criteria or set of standards to guide him, as he simply must decide based on what he deems as right and appropriate. This is one of the first points the poem makes on the process of making decisions. The choice between "good" and "bad" decisions is relatively easy. If poised in that situation, most humans would select the "good" choice because it is more desirable than the alternative. However, when pitted between incommensurate goods, the predicament becomes a bit more nuanced and we might become "stuck." There is nothing out there to guide us, other than our sense of decision making. This process, as outlined, at the start of the poem, is what haunts us all: "How do we make the 'right' choice when there is no 'right' choice, only being torn between 'right' choices?"
The speaker answers this dilemma with his choice. He selects the road that had been less travelled. There is a feeling that he could have selected the other road, if he had to do it all over again. However, the resounding concept we gain from this poem is that the speaker made their choice, he made his commitment, his decision between equally compelling ends. He made his decision, and while there might be some tinge of regret, or even contemplation about the what he left behind, his identity has been the sum total of his choices, and in this particular case the road less travelled, "And that has made all the difference." In making decisions, the speaker suggests that choosing a decision that we, as human beings select as desirable, that we, as human beings elect to stand for, and that we, as human beings feel is ours, become the best decisions we can make. Sartre once said that the most challenging component of a human being's existence is the need "to choose." Frost seems to be suggesting that this is where our greatest strength lies for if we select what we want, what we believe is right, and what we can defend, it can define us as who we are and make "all the difference."