Question: Why was the poet doubtful of being able to walk ‘The Road Not Taken’ in the future?
Answer: The poet is not too sure as to whether he would need to or be able to walk the other road. There is a tone of melancholy because he is unsure about the appropriateness of his choice, or perhaps he might be experiencing a sense of excitement in the event of the choice being right, for then, he would not have to walk the path he had abandoned.