For some older people the logic of the operating system is nearly incommunicable. They get keyboards, as they've typed. They can get a grip on a mouse. But after that they've got the face of a dog that's just been shown a new trick.
Not just older people. For a lot of people the GUI is the computer, and anything inside may as well be magic. I’ve known more than one who has referred to the whole computer enclosure as the hard drive.
