As nonverbal cues became increasingly legible to him, Mr. Robison also realizes that a longtime friend has been subtly mocking him for years. Mr. Robison’s marriage to his second wife, who suffers from debilitating depression, starts to decay. “When Martha had her down days, I was no longer able to jump out of bed and go to work,” he writes. “As soon as I got up I’d feel panic over her sadness.”

Image John Elder Robison

Most profoundly, he discovers that neurotypical humans are not, as a rule, happy.

“I had created a fantasy that seeing into people would be sweetness and love,” he writes. “Now I knew the truth: most of the emotions floating around in space are not positive. When you look into a crowd with real emotional insight you’ll see lust, greed, rage, anxiety, and what for a lack of a better word I call ‘tension’ — with only the occasional flash of love or happiness.”

Arthur Schopenhauer couldn’t have said it much better himself.

“Switched On” is subversive in more ways than one. In this age of heightened sensitivity to neurodiversity, one of the most uncomfortable notions you can raise about Asperger’s is that it can cruelly obscure the most basic elements of personality. The very idea is offensive and wounding to many people, because it frames a difference as a deficit; to wistfully suggest that a person with Asperger’s might be someone else without Asperger’s is to denature them completely, to wish their core identities into oblivion.

“Asperger’s is not a disease,” Mr. Robison wrote in “Look Me in the Eye.” “It’s a way of being. There is no cure, nor is there a need for one.”

In “Switched On,” Mr. Robison, 58, retains his Asperger’s pride. Part of him even fears he’ll lose his special gifts, on the (beguiling, I thought) theory that “perhaps the area that recognizes emotions in people was recognizing traits of machinery for me.”

But he is also torn. He did not come of age when “neurodiversity” was part of our vocabulary of difference. He did not come of age when “Asperger’s” was part of our vocabulary at all. He received his autism diagnosis at 40, and he has many memories of being bullied, losing jobs and mishandling social situations because of his inability to read others. His family is also a frightful caldron of mental illness, which further colored his self-image until he received his diagnosis. (For further details, see “Running With Scissors,” written by his brother, Augusten Burroughs.)

Mr. Robison still believes autism is not a disease. “But I also believed in being the best I could be,” he writes, “particularly by addressing the social blindness that had caused me the most pain throughout my life.”