Frost's classic "The Road Not Taken" is a truly inspirational and timeless work. The poet's goal is to inspire and challenge, and in this work he does so wonderfully.
What, on the surface, appears to be an account of a simple stroll through the woods is in reality a commentary on life itself because life is, when all is said and done, the result of the countless and constant choices that we make. And even choices as simple as the one described in the lines of this poem can have unexpected and profound consequences.
The reason the narrator is so excited about taking the road less traveled is because life can either be a chore or an adventure. One can either follow the course of least resistance, which is usually the more traveled road, or blaze new trails that will bring about not only new experiences and lessons for the traveler but also for those who follow.