This sounds like a question that your teacher would ask in order to get you to interpret the meaning of the poem for yourself and based on textual evidence. So you really must look at the text closely to see how certain words affect you and your thoughts about it. But one part of it that caught my eye was where it says, "I shall be telling this with a sigh/Somewhere ages and ages hence". The word "shall" means future tense, and "hence" means "from here", or "from this current time period". It seems to say that at some time in the future he will look back on the decision he makes. He's not going to say if the decision he makes is a good one or a bad one, he's just going to say that it made a difference in his life. Differences can be good or bad, right? But do I think he would take the same road if he actually went back later? Yes, I think he would because he says that he "marked" the other path so that he could find it again another day so he could go check it out. He just knew at the time that once you choose a path, other paths converge with it and we can get distracted and never go back. But if he had a time machine, I think that desire to go down both paths would have been taken.
Check out the link below for further insight. :)