Anyone who has used emacs seriously must aknowledge its imense power. The place most users see this is in the M-x command. Everything you do in emacs is a lisp function, and some of these functions are so called "interactive" functions. This means that they can be invoked from M-x. If something is a keyboard shortcut, it will amost always also be available from M-x. When I don't remember how to do something or don't know how to do something I start searching M-x. This is where you see the immense power of Emacs. And when you understand that you could in a few seconds write a lisp function, and evaulate it and have it avilable in M-x you see the insane flexibility of it.