Isn't that kind of difficulty with metaphor common among people on the autism spectrum? Any idea that Brun might be neurotypical seems to be getting remote.
Often, though it differs by situation and person. I can usually follow straight metaphors, especially when the dimensions are absurd (a dick shaped like a pencil) or the situation is like that. But with exaggerations, slang especially, or internet memes, or situations where speech isn't denotative but rather structured on mutual intrinsic understanding (think of situations where a couple dudes might do a complicated fist bump and clown around speaking incomplete sentences), I'm often lost. I didn't pay enough attention to the other students in my spec ed classes to really evaluate their responses, much less that I'd remember after 11 years.
@ case: reminds me that I recently watched an episode of A Place Further Than The Universe (spoilers in case anyone's watching), where part of a character's backstory was revealed, in which her track team "friends" had encouraged her, a first year, to go for the top at the competition instead of deferring to the third years, which was apparently a huge faux pas. Then those same "friends" told the third years who were pissed that they had told her to be more respectful, making her look terrible. and leading her to wall herself off.
I couldn't even understand the scene at first, and even after getting the japanese cultural parts explained to me, I still can't figure out "why". I've decided to just shrug and chalk it up to "they decided to bully her, that's just a thing that people do sometimes".