The months that followed Jack and Kirsten’s first night together show how daunting it can be for the mindblind to achieve the kind of mutual understanding that so often eludes even nonautistic couples. But if the tendency to fixate on a narrow area of interest is sometimes considered a drawback, it may also explain one couple’s single-minded determination to keep trying.

A Meeting

Kirsten was first introduced to Jack in the fall of 2008 by her boyfriend at the time, who jumped up from their table at Rao’s Coffee in Amherst, Mass., to greet his friend, who was dressed uncharacteristically in a suit that hung from his lean frame.

Jack, it turned out, was on his way to court. A chemistry whiz, he had spent much of his adolescence teaching himself to make explosives and setting them off in the woods in experiments that he hoped would earn him a patent but that instead led the state police and the Bureau of Alcohol, Tobacco, Firearms and Explosives to charge him with several counts of malicious explosion.

By the following spring, he would be cleared of all the charges and recruited by the director of the undergraduate chemistry program at the University of Massachusetts, who was impressed by a newspaper account of Jack’s home-built laboratory. Kirsten’s boyfriend, a popular Amherst High senior, had offered to serve as a character witness for his former classmate, and the three spent much time together that year.

The boyfriend told Kirsten that Jack had Asperger syndrome: his condition may have blinded him to the possibility that the explosions, which he recorded and posted on YouTube, could well be viewed by law enforcement authorities as anything other than the ambitious chemistry experiments he saw them.

But if Kirsten noticed that Jack held himself stiffly, spoke with an unusual formality and rarely made eye contact, she gave little thought to his condition, other than to note that it ran in families: his father, John Elder Robison, is the author of “Look Me in the Eye,” a best-selling 2007 memoir about his own diagnosis of Asperger’s at age 39.

After reading of the intense interests that often come with the condition — the elder Mr. Robison’s passion for Land Rovers, he had written, was the basis for his successful business servicing luxury vehicles — Kirsten and her boyfriend made light: “I have Asperger’s for McDonald’s,” she would joke. But Jack was all too familiar with the book’s more sobering stories, too: about the despair his father felt in his youth as he looked at happy couples around him and his rocky marriage to Jack’s mother, which ended in divorce.