I have temporal lobe epilepsy. The premise of this article seems quite wrong to me.

From the article: "I think it’s because I don’t only know things: I remember learning them. My knowledge is sedimentary, and I can “feel” the position and solidity of different facts and ideas in that mass. I can feel, too, the airy disconnect of a guess."

I think this can be rephrased as a statement that episodic memory (i.e. recalling the act of learning) is associated with semantic memory (i.e. recalling the fact itself). And for people with more normal brains, it seems it often is.

For people with temporal lobe epilepsy, in many cases the episodic memory isn't there. TLE frequently damages the hippocampus. Often, immediately after taking my meds, I can't recall doing so. I only know I did because I mark it in a notebook when I do it. Things like that are common. However, I can absolutely learn things like structure of systems, API calls, and the like. I believe that I perceive when I'm not sure of something, or that I'm guessing.

Of course, this kind of perception is difficult to verify outside of a study. A lot of memory is very unreliable, even for normal people. Us lucky people with TLE are often more aware of this, because in my case, I have very vivid memories of events that certainly did not occur. These memories are some of the most vivid I have; they seem more real than reality. I have memories of events that I can't verify by comparing them to the current state of the world; I have no idea if they happened or not. Even with all that, I believe my semantic memory is reasonably good; I can do my job as a software engineer.