He decides to start slow.

As he pulls out of the hospital parking lot, Matthew decided he needed to test his mother's condition. AGS was still extremely rare, and he'd never met anyone who had it.

"So, mom," he began, "the doctor said you'd have to stay home for a while, until you get over this cold." His mother's face scrunched up in confusion for only a second, until she smiled and said "Yes, that's why we came to the hospital. My cold." It was incredible. A single comment completely warped her reality. But what were the limits? "What a beautiful green sky today, huh?" His mother looked out the window, at the overcast, light blue sky, and again, she had that moment of confusion before responding. "Yes, it certainly is. It's a shame I'll be cooped up!"

Holy shit. She was really sick.