--Bruce Tognazzini, Tog on Interface, p.34
Users believe in the menu bar. The menu bar tells them where they are: in the safe, protective environment of the Macintosh, where consistency reigns.
The menu bar is the most constant object in the Macintosh. When it disappears, non-computer-oriented users assume they, the users, have moved, navigated, to a different planet, a world where all the rules may have changed. They are no longer within the familiar Macintosh world. And their only known way back, Quit on the menu bar, has been stripped away.
I have seen, during user testing, the very real fear etched on the face of users when the menu bar disappears. I have watched them literally panic as they realize they are trapped in a strange world.