Coleridge is exploring his inner self, lying bare his thoughts and feelings as they develop. And even though he gets into some deep philosophical territory (the idea that Nature is an "eternal language" that God uses, for example), he's still speaking from the heart, expressing his real concerns and opinions. "Frost at Midnight" is meant to provoke you to do the same thing, to analyze your own relationship with Nature, the Universe, and everything else. Of course, you might have a take that's totally at odds with Coleridge. (You might love barbed wire fences but totally hate trees, for example.) But the point of the poem is to get you to reflect on those kinds of experiences, and to feel a living connection to the world around you.