• Six-year-olds have very little agency over their minds and so little understanding of the world that IMO it’s not really worth it to view them as “guilty” of things.
• I don’t know whether this is a useful way of thinking about things for you, but most of the matter in your body has been replaced with new matter since you were six years old. I expect most of the way you think and the things you know have been replaced since then, and how your cognition works on a very basic level has changed. Like, if you’re over age 27 you have a developed prefrontal cortex that wasn’t all there before. You’ve changed enough that you could safely regard yourself as a different person in a material sense, and a much better person. Sometimes when I remember something terrible I’ve done ages ago, the way I’ll think of it is that I can destroy that other version of me by becoming a different, better person.
• You could see life-changing benefits by seeking therapy resources like DBT and CBT. Web searching these can lead you to free video resources that you could listen to while doing whatever else you do with your day.

Autistic adult here:

I do feel like I have a more childlike appearance sometimes, less so in recent years. I think that because of the seriously messy place my mind was in from the very start, it took me longer to interact with other people enough to develop the social awareness I needed to “fit in”, and not “fitting in” is often equated with being childlike, IMO. I still occasionally mutter to myself in public, have odd movements and posture, and generally act in a way that diverges from the social norms of the people around me, for better or for worse. Medication has changed all this around in ways that are too complicated to get into in one comment.

My mind never stopped developing. My brain chemistry changed as I went through puberty, and then through adulthood when the prefrontal cortex starts doing its thing. I kept gaining new knowledge from my surroundings and my peers and that changed how I thought about things on a basic level. There are certain specific areas in which I was always considered “more mature”.

My experience doesn’t necessarily reflect those of other autistic people who’ve had different hands dealt to them. I’d be happy to answer any other questions you have.