As an Autist/Aspie, I think the best advice for parents of people like me is to be flexible in your thinking even if we aren't. So many parents tend to think that they need to be rigid in their mind just like their kid is but this actually hurts the kid in the end. My own parents have had to change the way they think multiple times because of new information about me and what Autism is. I have also had to learn to be more flexible in my thought patterns, so, even though your child has rigid thinking, that can change if you, as a parent can be flexible and lead them, slowly but surely to the same way of thinking you can possess. But, not all will change, so don't ever force your views or thoughts on them. If your child doesn't want to change, you cannot force them to do so.