My autistic brother

This is my little brother Alex. He's two years younger than me and severally autistic. He can function in some ways such as going to the bathroom, bathing with a little encouragement, feeding himself, and entertaining himself on YouTube with elevator or roller coaster videos. He can't have a conversation or hold a real job or live in his own. He can socialize with those who know him by saying funny things he thinks of for them to repeat, like "sit down!" Or lines from a movie he likes. He sings in a humming gibberish way most of the day and stays up most of the night spinning the blades of a fan with the front taken off. His favorite pastimes include hiking, going to home Depot to look at showers, riding up the escalator and down the elevator at JC Penney and going to the beach. He is incredibly amazing with directions. In the car, if you follow his simple "this way, that way" directions, he will take you to the very beach house he went to one time last year which is 13 hours away.
As long as I can remember he has been this way, but I remember a time when something charged in him when he was a toddler. He was a happy healthy seemingly normal toddler. He walked and talked on time. One day the doctor suggested my mom skip the several appointments she had lined up and just get all of those vaccines in Alex in one appointment. My mother trusted the doctor and went for it. Within a few days after, our sweet smart little Alex got very very sick. With his sickness, he screamed in terror constantly and also stopped walking and talking. Even after his sickness subsided, he still didn't walk or talk and was set back about a year in development. As he grew, he didn't progress like he should have and he was very violent and became1. item diagnosed with severe autism.
I love him the way here is but I often wonder if he be different if he hadn't been overloaded with shots that day. I wonder how he would be as a typical, not autistic 22 year old today.