As added support for this view, I can contrast with the relatively uncommon experience of having some experiences unified: when listening to an audio book, my brain often (but not always!) ties the experience of the book with my physical location at the time. When I return to that location, the experience of being there is inextricably tied to the portions of the book I heard in that place. I can't really remember one without the other.

But this is unusual. Most things are not tied together like this. In the author's example, I can separately remember the philosophical musings that were in my head on a drive, and the feeling of the steering wheel (which normally would be too mundane to remember, but on a hot day the cover will get sticky and I'll be very aware of that). There might be a weak association from one to the other, but usually not much at all.

As a tangent, I wonder if LLM attention heads are doing something analogous. Each is associated with a strand, sometimes combined with the others and usually not? (I don't know enough to say whether this matches at all.)