Last passage of the book.

In the last part of the book ("I had a sense of coming home to myself, and of having found out what a little circle man's experience is. For Antonia and for me, this had been the road of Destiny; had taken us to those early accidents of fortune which which predetermined for us all that we can ever be. Now I understood that the same road was to bring us together again. Whatever we had missed, we possessed together the precious, the incommunicable past.") what is the main point Cather is trying to get across and how does it relate to the rest of the entire book? Is there a reason the word "Destiny" is capitalized?