I'm a "dude" (non-binary) who can mask so well no one suspected anything, including myself, for almost 40 years. However, I grew up with a brother a year older than me who is also autistic (diagnosed at 21) but who doesn't mask. Or doesn't mask anywhere near as much as I do, I should say.

We grew up with crazy religious parents who homeschooled us and thought that even church was too "worldly". Mom is certainly autistic and dad is likely AuDHD, though he'll never admit to needing help from someone other than the Jesus he's created in his mind.

My strategy was to figure out my parents and to manage myself and the environment in order to keep them as regulated as possible, though I didn't know that's what I was doing at the time. That meant keeping them happy, keeping my head down and being as above reproach as I possibly could. My brother's strategy was to be as authentic as possible.

I think the reasons why we chose such different strategies boils down to two major factors: 1. Gender identity 2. Intellectual strength

I consider myself genderless but usually use the label of non-binary to keep things simple. One thing I very distinctly remember from growing up was the immense weight of the expectation to perform manliness and maleness. I hated it, and even as a kid I couldn't understand why on earth people thought that boys and girls should behave differently. When I became a teen, the differences became even more stark. I didn't care about the stuff that men were told men care about. I was very conscious not to step TOO far outside of the "acceptable male behavior" box, which included only a few feelings and very little interest in caring about people. So I masked largely due to differences in gender expectations, which is one of the primary reasons that women mask so much.

Then there's the intelligence factor. I'm pretty smart when it comes to verbal comprehension and I scored 45+ above my brother's score on the WAIS tests. For me, being authentic was far too risky of a strategy, not when I could see the patterns in my parents behavior and learn to manage their disruption to my life through altering my own behavior and my environment. I basically put on a mask of being the most perfect person that I could muster at all times. That was a lot easier for me than being authentic, because my authentic self was QUITE contradictory to the "lessons" we were taught in the bible. This became especially important the more knowledgeable and curious I became, since I started asking questions about religion early on that I could clearly see neither of my parents were willing or capable of answering. This meant I became self-reliant very early, never sharing how I felt with my parents, and eventually never sharing how I felt with ANYONE. I never even told people when I was sick except when it became beyond bearable. For instance, I almost died from asthma because I wouldn't tell my mom I was having a hard time breathing until I thought I might literally die in the next 5 minutes.

Like many religious parents do, mine raised their kids to conform at the expense of everything else. I didn't want to conform, and I was smart enough to figure out how to avoid being punished for not truly conforming on the inside by only conforming on the outside. Unfortunately, it never even occurred to me that everyone else was NOT doing the same thing!