And then he looked at a photo he had snapped and saw it. It was a simple enough question. But the answer was "like a punch in the gut," Cornelius told ABC News.
"No One." That was his son's answer to the question, "Some of my friends are ..."
In a Facebook post that's now been shared more than 12,000 times, Cornelius detailed his thoughts on not only his son, but how children everywhere who don't fit the mold are being excluded.
If you would like to write to Christopher, you can mail him at the address seen in the Facebook post.
For more on this story, go to ABCNews.com.