He’s also become something of a social media darling on Twitter, though he does not have a Twitter account, and routinely receives VIP treatment when he travels to other tracks around the country.

But about that pony.

“One year when he was probably around 10 or 11, he rode a horse for the first time, and he loved it,” Megan said. “He continued on with therapeutic horseback riding, which was amazing for him – amazing.”

She said that the horseback riding — which he continues to this day — helped him to follow directions better and develop empathy. More important: “He really has a bond with the horses,” she said.

He rides weekly, and each lesson begins with Matt walking his horse that day around the ring and chatting with it.

“He would talk more to horses than people when he was young,” Megan said. “And he would talk to horses during lessons and tell them all about everything.”

These days Matt can recall each of the horses he’s ridden over the years. “Nina, Sunny, Maggie, Cajun, Addie, Bella, and Skye,” he said, ticking them off. 

Cajun, whom the Halters subsequently adopted and now lives with them, was one of the first horses Matt rode, a former outrider’s pony with a heart-shaped blaze who “looks remarkably like Animal Kingdom.,” Megan said.

Cajun made Matt an Animal Kingdom fan — well-timed, since the Graham Motion trainee won the Kentucky Derby in 2011. And while Animal Kingdom was stabled there, Matt got a Fair Hill tour from Sally Goswell, manager of the Fair Hill Training Center, and a chance to meet the champ up close.

“Matt specifically wanted to meet Animal Kingdom,” Megan said. “She took him there, fed Animal Kingdom peppermints, and he fell in love with horse racing ever since.”

His racing fandom continued in relative anonymity until this past April. That’s when Megan posted a picture of him wearing “Horses for Autism” swag and beaming. That got a dozen likes.

A month later, she Tweeted a picture of the sign they’d made to congratulate another Graham Motion trainee, Mean Mary, on her win in the Grade 3 Gallorette at PImlico May 15.

“Congrats Mean Mary,” it read in big letters. Beneath that, much smaller: “Go Herringswell Stables,” referring to Motion’s racing operation.

That got 40 retweets and 365 likes; a social media star was born.

“His smile is kind of magnetic, and his enthusiasm is just off the charts,” Megan said. “It’s really been bizarre the last couple of years, but especially this year, how much people gravitate towards him.”

While the social media aspect of Matt’s fandom is perhaps the most visible, it’s a different kind of social relationship that’s most important: his friendship with Cedeno, Delaware’s six-time leading rider who is likely to finish second in the jockey standings there this year.

“Having a fan like Matt is incredible,” said Cedeno. “We have a really special relationship, and I am so happy to have it.”

“I don’t know if he picked Carol out because she was always winning,” Megan said. “Maybe he likes her smile; I’m not sure. But he just started cheering for her more than any other rider.”

One evening, riding at Penn National, Cedeno came off her mount and was injured.

“Matt had a panic attack,” Megan said.

Megan reached out to Delaware Thoroughbred Horsemen’s Association executive director Bessie Gruwell — whose 10-year-old great-nephew Carter is autistic — to see if Cedeno would mind if Matt texted her. Gruwell reported back that it would be fine.

“We started developing that friendship,” Matt remembered. “We texted her every day, twice a day.”

What do they text about each day, twice a day, at 6:00 a.m. and 4:00 p.m.?

“Everything,” Matt said.

“He has my phone number and we text, and we also follow each other on Facebook, and he is always telling me about the horses I ride and their owners and trainers,” Cedeno said. “He knows everything about them, and he is incredibly smart.”

Experts say that people with autism spectrum disorders tend to develop single-minded passions. What’s more, they sometimes retain those passions as they age, even though those passions might be geared for younger people. That can make adults on the spectrum something of an admixture of adult and child.

Matt, for example, is an avid handicapper who reviews the program, he said, with an eye to “performances that really stand out to me,” such as “dropping in class… [or] impressive figures.” On one recent Saturday at Delaware Park, Megan said, he helped a couple of other ‘cappers win “a boatload of money.”

He’s also a guy who begins each day by tending to the miniature Delaware Park that he and his father Mike constructed in the yard, one that’s complete with a turf course, winner’s circle, starting gate — even the right kind of flowers.

“I’m not sure” what made him decide to build it, Matt said. But when asked if he has fun with it, he replied, “Yeah, I do.”

With Gruwell’s great-nephew Carter, Delaware Park now is home to two prominent young autistic fans — though they often find themselves on opposite sides of the fence, rooting interest-wise. After all, Matt has his connection to Cedeno, while Carter helms the Angel Suarez fan club.

“They get over there and Carter’s cheering for Angel Suarez, and Matt’s cheering for Carol,” Gruwell said with a laugh. “And, you know, they go back and forth.”

Megan and the Gruwell said that they have been batting around the idea of an Autism Awareness Day at Delaware Park. While both said that’s not likely this year — not enough time left in the meet — in the meantime, an Autism Awareness race might be in the offing.

Of course, anyone who goes to Delaware Park, or who follows racing Twitter, well, there’s a pretty good chance they’re already aware of Matt. 

It’s clear what Matt gets out of horse racing: joy. You can see it in the smile on his face, hear it in the excitement in his voice. 

Beyond that, Megan said, his racetrack experiences, particularly his newfound celebrity, have helped him develop “his ability to interact with others,” a skill particularly challenging for many on the autism spectrum.

Megan said the family has received almost nothing but good will and support from the racing community, and perhaps that’s to some extent because of what Matt, with his boundless enthusiasm for the sport, has come to many to represent. What, in some sense, the sport gets out of Matt.

“I’ve actually gotten a lot of people reaching out to me saying how much he inspires them,” Megan said. “He really touches a lot of people. A lot of people have reached out to me and said, you know, he’s a breath of fresh air in this sport.”