>>In my family, we are known for our strange "subject hops" mid-conversation ...We used to call it 'grasshopper logic'<<

We called it "leaps in logic" and then there were inside family references that - although seemingly unconnected to the subject at hand - were a perfect riposte in the conversation for family members ... . usually followed by laughter.
Then, there's good old Imagination and Oblique Thinking.

Years ago I heard a psychiatrist posit that there are two types of ways people coverse : those who finish each others' thoughts and people who never interupt. Makes for interesting times when the polar opposites meet!The MD called for a recognition of the differences to avoid misunderstanding the behavior.

In earlier post here I mentioned being "in the zone" sometimes when writing ... say I'm writing a scene in a narrative ... it's like a movie running in my head and I have to get it down fast. I can see the people, hear the vocal intonations, see the room, and what everyone's wearing, what they're doing while talking and at same time my brain is choosing the words to convey what I'm "seeing and hearing" even though I am really making it all up!
Other times the scenes come hard and they're the ones that require many rewrites to get the same flow.
Hard to explain.
My book is now hundreds of pages long...maybe someday it will be finished ... I can hardly wait to see how it turns out!