Australian Man Didn't Realize He Had Autism Until His Daughter Was Diagnosed

Chris Offer, of Australia, said the diagnosis was "immensely helpful."

Chris Offer, 33, a father of four girls, told ABC News he was diagnosed with autism three years ago after decades of feeling like he was "quirky."

"Imagine that all your life you're trying to be...held in this normal box and no matter how hard you try, you find it hard," Offer said. "And then someone goes, 'Well, that's because you're not normal.' It's freeing."

According to Autism Speaks, an autism advocacy organization in the U.S., more research is needed to determine the prevalence of autism in adults. More than 2 million people are on the autism spectrum in the U.S. and tens of millions are living with autism worldwide, according to the organization.

Offer's diagnosis was also a surprise to his wife. The two have been together for 10 years.

"He's always been quirky. He's always been kind of unique. He's always paid more attention to detail where I'm more scattered," the 28-year-old told ABC News. "So I've always really loved it because he contrasts my personality. We never looked into it because it was never a problem in our relationship."

Still, Offer, who lives north of Brisbane, Australia, admitted that the two had many arguments early in their relationship because it is hard for him to look people in the eye when making conversation.

"I have to make myself do that," he said.

Although he had never heard of autism when he was younger, Offer said he is now "better equipped" to deal with everyday life.

"I'm still doing the same things that I'm always doing but I'm doing them differently with more of a conscious mind," he said. "The diagnosis gives you a better toolbox to deal with everyday life."