I'm one of the stupidest people I know. But I'm a high-functioning moron, and I have enough intelligence to know that stupidity is a negative trait, so I do my best to cover it up. I write blog posts or I tweet, trying to present a superior aptitude, but I can't do anything. I can't read quickly or for comprehension. I can't write a flowing argument. I can't concentrate on anything if there is the slightest noise. I can't understand basic concepts that everyone around me knows by heart. And on the off chance I happen to learn something, I can't retain it for any appreciable length of time.
I especially cannot understand modern life. New experiences and activities are beyond me. Everyone else does something new and learns from it, then can do it again. I just get angry and demand that someone be held responsible for not telling me ahead of time how to do it.
I was raised to believe that any self-criticism is just a ploy for attention (and the underlying assumption is that a social creature such as a human should never desire attention). Because of this, I feel the need to specify that this isn't an "I'll say I'm dumb so you'll say I'm smart" scheme. This is just honesty. I'm an idiot. And to cover my idiocy, I've pursued a level of education and a line of work that are typically associated with smart people, because then I can say, "Of course I'm not dumb, look at my job and credentials!" So I have no one to blame but myself for my failures at school and work.
I worked in a garage door factory once. That was probably the only job I've ever had where I wasn't worried someone would discover my ignorance. I could handle that job. Maybe that's a good indication of the level of job I'm actually supposed to have.