The first time I sat down at a NeXT cube, I couldn't figure out how to turn the thing off. Spent a minute or two feeling around the back until someone said "pretend it's a Mac" and I realized the power button's on the keyboard.
It's running Windows 8, but using the Classic Start Menu and we have reviewed the start up, log in, log out, and reboot dozens of times. Kids do not know more about computers just because of smartphones.
Random student, although they've been a part of our pilot program and have done this before. I think it's an issue of them not thinking they can do it without help. They all think I'm a sorcerer because I know the WIN hotkeys, lol.