There is nothing as mild form of autism. Sometimes, symptoms are masked throughout our lives. This can take a huge mental toll on a person even if it is not outwardly noticeable to the rest of the world. I was diagnosed as an adult, and a while ago I would have been labelled as Asperger or high-functioning. However, because I masked so much my mental health problems went largely untreated. I confused therapists and became chronically depressed and anxious. I was a self harmer and had a lot of meltdowns and shutdowns when I lived alone at uni. So even if a person appears to be neurotypical, there is usually a lot more going on that is taking a lot of effort. I am also not saying autism is a bad thing. Sure, my autism has caused me some harm, but it has also allowed me to focus on tasks that interest me in great detail. It has also allowed me to excel at non-verbal forms of communication such as art, writing, and dance. So autism in itself in my opinion is neither mild or severe. What is most disabling about autism is living in a world designed for people who think and act in a different way from you.