It was supposed to have been a spectacular Sunday in New York City for Paul DeSavino.
He and his mother, Marlene, were on their way to Carnegie Hall, where he was one of a group of piano students giving a recital. The others were already there, taking turns warming up. But Marlene DeSavino sensed that there was something wrong with her son, the only autistic performer in the recital that day.
"When we got to the rehearsal and he played, I knew immediately as soon as he played the first couple of notes that he wasn't focused," she said.
Watch "Nightline" tonight.
Chopin's Prelude No.4 is one of the sweetest and gentlest melodies ever composed. And Paul was just chopping at it.
"I gave him clues and cues while he was playing it -- you know, 'Softer, good, good, that's right,'" Marlene said.
But the problem with Paul was entirely in his heart, as he had previously told his mother.
"He said that he thought that he was in love," Marlene said.
Paul told her later he was in love with an older woman. But problem was the woman didn't love him back. Unrequited love weighed devastatingly on Paul.
Who knew that a man with autism could suffer the pain of a broken heart? Does it even make sense that an autistic man is in love?
"Am I to say that what he thinks is love isn't love?" said Peter Gerhardt, executive director of Nassau Suffolk Services for Autism. "For him, it's love. And that's OK."
Gerhardt does not know Paul personally. But as one of the first psychologists in the nation to work primarily with autistic adults, he concluded long ago that autistic people are as likely as the rest of us to stumble into human attraction.
"First of all, it's part of human nature," Gerhardt said.
"He just wants to be with her," Marlene said. "He wants her to be around."
The object of Paul's infatuation is the director of a job-training program he was enrolled in for several years. It's a relationship that could never be, some of his closet confidants say.
"Feelings of love are so complex he doesn't understand the nuances," Marlene said.
And how do you explain that to a man who is otherwise always encouraged to go for it, to experience the pleasures and challenges the rest of us enjoy to the extent he can. Paul is told to enjoy things like sports and music.
He has a job as a volunteer errand-runner at a New Jersey hospital and lives with several adults in a supervised home of their own.
We filmed scenes of Paul in his home and at work for a "Nightline" special on autistic adults. This was a good time in Paul's life, before the heartache. But on that earlier visit -- when Paul showed me his room -- I learned that he'd had an earlier infatuation, with another teacher.
Paul is heartbreakingly naive in so many ways but especially about relationships.
To express his feelings for that earlier teacher he started wearing the same eyeglasses she wore, even though he has 20/20 vision.
"I can't believe how much I loved her," Paul said. "Well, she's a mother now."
The idea that autistic people love the same as everyone else is new to experts.
"The kids love their moms, they love their dads," Gerhardt said. "They will snuggle up. Yes, there is that classic distance, or they are not looking at them. But they'll sit next to mom and tuck themselves underneath their arms. That's love in his terms."