I also guarantee that you have many behavioral quirks and ways of thinking that are VASTLY different from the majority, and that you're unaware of them because

I also guarantee that you have many behavioral quirks and ways of thinking that are VASTLY different from the majority, and that you're unaware of them because you haven't yet recognized the difference from a "normal" person. Well, that's the thing. I don't really have those. According to my therapist, I wouldn't be diagnosed based on my behavior in the years she's known me. However, the stories I've told her about my childhood seemed pretty striking to her, and the outward manifestations of mild autism often diminish over time, so she suggested it might have been a significant factor in my childhood without being apparent at this point in my life. Hence the need for a specialist to diagnose me.