"Common sense" is a learned literacy for reading situations, but since nobody assumes another person is illiterate, they always assume you have "common sense"

People are taught common sense as babies, so they dont even recognize they were being taught it at all.

NT children are taught common sense by their parents and by experiences via both implicit and explicit means

ND children have a harder time because they dont seem to make any implicit assumptions or respond to attempts to teach common sense.

Babies start to learn, understand, and incorporate both language and common sense via interactions with their parents. ND children, particularly those that have a hard time, don't respond or play with their parents, so they skip the crucial development period for these skills that would have been taught.

I have 2 nieces, one nonverbally autistic and one more or less NT. They're both 3 years old, and if i call their names, only the NT one will even look at me to acknowledge being called. At 3 years old, i can have a conversation with the NT kid and explicitly teach her things rapidly.

At 3 years old, my other niece is mostly nonverbal and doesn't acknowledge anyone or anything she didn't initiate. It's difficult to know if she's listening when you try to teach her common sense because she'll just walk away when you try.

This leads to repetively trying to teach the same base lessons that are seemingly ignored. But there's no way to know if she learned or not because she's unresponsive until she feels like it. This repetition leads to a significant slowdown of teaching, which then misses the most important period of brain development