What is the thesis statement in "The road not taken"?

I my view it would be that feeling regret about making the wrong choices is irrelevant and useless; the important thing is to follow one's heart and avoid choosing one of the roads because it has been taken by the majority of people. Furthermore, the road less traveled is not necessarily the road that has not been chosen by the majority of the people but actually the road that has been chosen for strictly personal reasons, regardless of how many people chose to take it.

Finally, the poem's metaphor is very Christian, it is very similar to the New Testament verse, Matthew 7:14: "But small is the gate and narrow the road that leads to life, and only a few find it."