Two, (maybe three,) of my kids are Autistic. One has a professional diagnosis, the other an educational diagnosis. While learning more about autism, and seeking advice from Autistic adults, I recognized myself. It was not immediately obvious. We learn to cope. We learn to hide our Autistic traits from an unkind world. We hide who we really are, so the world doesn't know we are disabled. The more I learned though, the more I knew that inside, who I really was, regardless of how well I've learned to fake being neurotypical, was an Autistic person. I went through the diagnostic criteria to see if perhaps I just "had some traits," but no, it was so clear.
I'm also an anxious person. I don't take anything lightly. I don't want to make false claims. I desperately wanted community, but not with those that were not truly my community. I decided I needed some kind of confirmation. As an adult, presenting as a woman; (I'm nonbinary,) I knew this would not be easy to get.
So I settled on discussing the issue with a psychologist I already had a relationship with for other reasons. I knew I wouldn't be able to adequately speak to it, as I verbally shut down at emotional times. So I wrote him a letter, 3 pages, single spaced, explaining why I think I do indeed meet criteria. I gave it to him in advance of our appointment. When I arrived for the appointment, he told me he had read through it several times. His response? "You need me to tell you what you already know?" (He then went on to confirm that he agrees with my assessment.) This is it in a nutshell. We know ourselves. Presume competence. Believe us when we tell you we have thought long and hard about this, and have read the criteria.
Since that time I have joined the Autistic community in full force. I've made wonderful friends. I think I've helped some people with my advocacy. I am glad people have not shut me out of advocacy because I lack a piece of paper. We are all in this together.