It seems hard to believe that there are people out there who have never used a computer at all, ever, and yet they exist, and they are in fact quite numerous. Worldwide, they probably outnumber those who have.
Read this article by Jennifer Boriss for a fascinating story of man versus machine:
I give him the same task: find a local restaurant. He stares at the screen for awhile with his hand off the mouse, looking confused. I ask what he's looking for. "I don't know, anything that looks like it will help!" he says. Finally, he reads the Apple context menu at the top of the screen, and his gaze falls on the word Help.
"Help, that's what I need!" says Joe. He clicks on Help, but looks disappointed at what he sees in the menu.
I wonder how Joe would feel if he was presented with an iPad instead. He might be even more confused... but at least he wouldn't have to learn how to use a mouse, windows, and so on.