Picked agepill, but my actual answer is the "arrested development pill", that is: it takes life experiences to make new life experiences.
If you're autistic, you can't have a normal childhood, therefore you'll be missing those experiences as you enter puberty, so you can't have normal teenage years, and it all snowballs until you're old but never learned things kids learn early. And nobody teaches an adult sperg obvious things, such as how to carry conversations with NPCs.
Arrested development also happens with sheltered kids, helicopter parents etc.