so... if I click "cancel"... then what? does something not happen? or does nothing happen? or both?
If you click Cancel, something new will happen: the dialog will close and the total amount of entropy in the universe will increase slightly, hastening the heat death of the universe and thereby dooming us all.
If you click Okay, the dialog will close and the net entropy in the universe will increase also. However, this may be slightly different, depending on the location of the mouse cursor and/or your fingers when it happens. If you hit the Return key on the keyboard, the net entropy gain will be slightly reduced, thereby postponing our inevitable doom, unless the mouse pointer was already over the Okay button, in which case it's six of one doom, half a dozen of the other doom. If you do nothing, the Okay button will pulse, thereby resulting in more entropy and--you guessed it--our inevitable doom.
No matter what you do, we're doomed.