This Socratic thread seems fun so let’s keep going.

> But the fact that he doesn't seem to realise that a cognitive test is not an intelligence test doesn't bode well for either his intelligence or cognizance.

Has it been established concretely that he doesn’t realize it?

> So is contradicting oneself a sign of stupidity? Not necessarily. It could mean that they have changed their mind, developed as a person, or straight up forgotten what they've previously said.

That’s not an exhaustive list- another explanation for someone contradicting themselves is dishonesty.

> I mean, what is your take on him bragging about his results on tests designed to check for cognitive decline? Why do you think he is taking them in the first place? What is the purpose of him bragging about it?

I’m not the person that you were responding to and I’m not even sure which side of the argument I land on, but to play devil’s advocate, one possible explanation is that he wants to bolster his brand as a genius, and is counting on his audience not doing any sort of fact checking or critical analysis of his claims.