DocC:

The question about how readers here distinguish concrete from abstract thoughts is simply one of curiosity. I'm interested in reading how we define that line that separates the two. I expect there to be a gray area.

But the question on the other thread about pneumonia came from researching pneumonia on the internet. I thought I might have pneumonia, self-diagnosed it, and then became interested in some of what I was reading about it, particularly nursing home pneumonia. [My doctor is treating me for acute bronchitis, but I still think I have pneumonia. ]

Edit: Zed, I just read what you just posted about the use of proverb interpretation to help determine brain injury--very interesting!