I had to ask Chat GPT what that meant, It thinks you mean “You seem so sure he’s just pretending—are you ruling out any actual risk?” No. He is really far gone but his father was showing symptoms of Alzheimer's over 20 years before an official diagnosis was made. Mostly as Donald was milking him and didn't want him declared incompetent and a judge or other given power of attorney. Due to his older brother's alcohol suicide, it's hard to guess. Also his mother was another of his early death due to his usual negligence cases.
No, you see when I was growing up I was punished for being a mental spastic and I figured it out. Cruel to be kind. I'm a pilot now (Idiocracy reference).