...the way he uses these two stories—it’s as if he is trying to harness something he isn’t able to say. I have often used that method, combining things that don’t obviously go together and making the bet that, by doing that, I am going to access something that is in the realm of the unsayable. It’s something that works in psychoanalysis and I think in literature, too.
This is indeed something that happens very often in psychoanalysis, at least the sort of psychoanalysis I do. People try to free associate, and when they do that, they talk about things they describe as "unrelated." Sometimes it is a dream and a memory. Other times some quotidian thing that happened at work and a song they can't get out of their heads. Sometimes it is more than two things.
Other times, people don't present stuff as a list of unrelated things explicitly. They talk about one thing at the start of the session, then switch to something new without prefacing the switch. Soon they are off on some new thing. (These of the people who are good at free association).
I like listening to these sorts of "unrelated things," and I've started to think of them as a formation of the unconscious, on the same level as the slip.
What is so interesting about these things is that they often seem connected and can thus be rendered into an interpretation of sorts. "I wonder what you'll think of this, but as you described these things, I noticed a possible connection..."