Secretly disabled

You ever worry that maybe you're disabled/retarded and you just don't know about it?

Like you know how people with down syndrome are dumb and might be blissfully ignorant, unaware of how stupid they are, unaware of what they're missing out on, or how people see them and treat them differently? I wonder if I'm like that to other people. Maybe I'm crazy or retarded and everybody but me is aware of it.

Have you ever had doubts like this before?

Sometimes I have this weird fear that what I see is all a dream, but my body in the real world is still doing the movements I am doing to get the results in the dream.
So for example, when I'm taking a shit in toilet in the dream, in reality I'm taking a shit in the middle of a seminar.

But no, I don't fear that I'm disabled.
If I was retarded, I wouldn't have the brainpower to come up with this complex world.
My view of the world is complex and achieves results. It "maps" to the real world.
If I was retarded and my world was a simplification, my methods wouldn't work.

There is still a possibility that I am simplifying the world and the real world is far more complex, but then it would need to be a massive conspiracy of vast majority of people acting simple on the outside, but having godlike intellects on the inside, and having strong motivations to fool me.
Everyone would have to play along with me. Many people would have to very consistently pretend to be dumber than me, just to keep me from "waking up".

Since a grand conspiracy to fool one guy is very unlikely, it's irrational for me to believe I'm too dumb to understand that I'm dumb. The only option that makes sense is that I am indeed as smart as I see myself being.

I used to worry about that until I realized I definitely am mentally disabled, prior to the realization I had wondered if I just had a 'scary look' or something. My expectation: if you have to worry about whether you are disabled, you are.