I noticed this old man having conversion with himself.
I am not sure if talking out loud to yourself is some kind of disorders like schizophrenia but this probably has something to do with loneliness or neglect in the later part of life when you need care and someone to talk to and share your feelings.
There is another side to this. Geniuses like Albert Einstein talked to himself. May be this helped him in clearing his thought process.
Have you noticed anyone in your daily life-like this and what are your views on this?