Close reading

When you read a poem, read each line carefully and try to understand the meaning behind the words.   

SEARCH for HIDDEN meaning!

Now let's do a close reading of "The Road Not Taken." The poet says that he is "sorry [that he] could not travel both." And he tries very hard to "[look] down one as far as [he] could." What is symbolized by this action? Is there no turning back once he chooses one road?