Find it here: https://www.fanfiction.net/s/7239464/1/Different-Not-Defective
Everyone said Harry was different, but what if the differences were more than just surviving the killing curse?
What if Harry had Autism? How would the wizarding world react and adapt to The Boy Who Lived?
As quoted, Different, Not Defective has "one of the best interpretation of Autism", it has "a lot of realistic scenarios and more subtle systems of Autism".
On top of enjoying the fanfiction, you get to learn more about Autism as well as why people who are autistic do what they do. It teaches us that deep down, they know they are different from others and they want and yearn to be accepted and love as well.