My Ántonia Memory and the Past Quotes

How we cite our quotes: Citations follow this format: (Book.Chapter.Paragraph)

Quote #10

I had the sense of coming home to myself, and of having found out what a little circle man's experience is. For Ántonia and for me, this had been the road of Destiny; had taken us to those early accidents of fortune 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. (last paragraph)

It's interesting that Jim chooses to call the past "incommunicable," given that he's just written a memoir – a act of communicating the past. What do you think he's getting at in this final line?