Why might the poet titled the. poem the road not taken but at the end of the poem the speaker says that choosing the road less traveled has made all the difference?

Robert Frost may have named the poem The Road Not Taken to show that the "road less traveled" is often an objection to conformity. Taking the normal path of life usually has a more predictable end or result, whereas taking an alternative path would give you a result different from that of the rest of society. Choosing a more unique route makes "all the difference" in the outcome. 

Is there a dictionary to use?