Maybe if I bold it you'll answer the question. Why are you sure he doesn't have dementia? You said he definitively doesn't have it.
You don’t know me and you’re already talking down to me like I haven’t had that terrible life experience. I wouldn’t be so confident if I were you. Especially when you say things like “That sure looked consistent with early dementia.” Like, bruh.
That's a "how dare you", not a no. Anyone saying that an old person will be the same one year to the next hasn't experienced that they very much can change over the span of a year. Like, that's a crazy statement to make with regards to the aging of the elderly.