Some boy too far from town to learn baseball, (Line 25)
This detail sums up the way that the geography can limit a young boy's contact with his peers.
Whose only play was what he found himself, Summer or winter, and could play alone. (Lines 26-27)
Here we see the positive consequences of isolation. For example, isolation from other boys and girls had fostered a sense of ingenuity and creative thought in the boy.
And life is too much like a pathless wood (Line 44)
The pathless aspect of the wood is isolating, in that it limits the speakers ability to get on "a beaten path" at the expression goes. More companions or attachments would create a path, but since he is isolate, he has to go alone.
I'd like to get away from earth awhile (Line 48)
What is the speaker hoping to gain from escaping to heaven? Does he hope to alleviate his feelings of loneliness, or does he hope to separate himself even further?