My cousin borders on answering "What's the time?" with "I don't know." instead of actually checking the time and reading it to you. Not because he's lazy or unintelligent, but because he has autistic traits.
He's not intuitively aware of the mental states of other people, so it doesn't always occur to him that a question could express an instruction to carry out a task, as opposed to merely inquiring about his immediate knowledge of the current state of affairs.