He said “I don’t get it,” in a way that made me realize: “he does not understand at all,” and that an explanation, in this case, was not necessary, could not help.
I don’t think he understood that either.
And then I pictured myself having to explain everything to him all the time, forever, because, it seemed, he might never understand, and so I just smiled and shrugged, though it’s possible I overthought it, and also no longer understood things too.