I guess Chris lacks the understanding that other people don't necessarily know things he knows and that their way of thinking may lead them to come to different conclusions even if they do.
There's an experiment with little kids, where they see two people in a room putting an object inside, say, a cupboard. One person then leaves, the other puts the object into another cupboard and the first person returns. The kid is then asked where the person that left the room will look for the object.
Depending on their maturity, they will either say the person will look in the cupboard where the object is or where it was.
Below a certain level, they will not contemplate that the person that left did not witness the object being transferred and thus assume that the person that left has the same knowledge that they do. So they will assume the person will look in the cupboard that the object actually is in.
At a later stage of brain developement, the kid will say the person will look in the cupboard where the object used to be, since that's what they infer the other person to know themselves.
Chris oftentimes made me feel like he assumes that things that he knows should be things that everyone else knows, cause he never bothers to really contemplate if other people can even know or be aware of something or not. And he rationalizes a lack of knowledge as people around him being dumb, which also feeds into his shtick of thinking he's a rainman type savant.
Another aspect of this is when he comes up with riddles, like he'll post an image of Mac&cheese and go "what is the hidden meaning?". To him, Mac&cheese are Italian food, so that makes him think of Peter Griffin going "Aboobity beepee", which makes him think of Family Guy, which makes him think of Megan Griffin, which makes him think of a purple hat.
So, to him: Mac&cheese = purple hat.
No one would be able to come to this conclusion, but to Chris it's super obvious, if not outright inadvertable, like railroad tracks. If someone does not manage to solve this riddle, clearly they are dumber than Chris.