I could write u a book, my eldest son was 25 on Sunday and he has mild autism, I just have got used to giving him space, not pushing him to do anything and making sure if he has to do anything or go anywhere he is covered for any change in the plan, route, event anything, the slightest unexpected thing and he turns round and comes home. he has to be in a routine and whilst he is highly intelligent and extremely academic, slight problems can cause the most violent and aggressive flare ups. I have to say that he is improving and the incidents are far fewer as he gets older, he still loses things, breaks things accidentally but doesn't remember it being his fault, and can tell u every planet and star constellation in the heavens but does not know how to drive a car and says they are the tool of the devil and will explain at length about how cars will ultimately kill us, I have little advice except treat him as an adult and let him have space and keep things simple for him on a day to day basis.