To be, or not to be.
If, like a narcissist, you identify with your IMAGE instead of your inner SELF, you identify with an apparition, and logic dictates that you have an existential problem if it disappears. I cannot imagine being in such a state, and I doubt any normal person can. But it is well documented that narcissists say they feel "empty inside" and that they feel they "do not exist" when alone — that is, when they have no mirror.
This is, of course, just childish make-believe. Narcissists make-believe that their false image is their true self. But narcissists aren't the only ones who delude themselves. To hear people make-believing a fantasy, just listen to the left-wing-nuts (and the much less common right-wing-nuts) who call in to comment on a C-SPAN broadcast.
My favorite example occured after a broadcast of one of Senator Kennedy's outrageous performances, in which he abused a Supreme Court nominee he was questioning, while yelling a string of absurdities and boldfaced lies about him right at him. One woman must have been halluciniating some other reality, because she called in afterwards praising and thanking and virtually canonizing the Senator from Hell as some kind of St. Michael the Archangel for fighting to save the world from his "evil" (defenseless) victim.
This is simply lying to yourself about what you're seeing and hearing, often done by simply filtering out unwanted information so that the rest paints a picture you like. This is self delusion, intellectual dishonesty, make-believe.
It reminds one of the stupid question If nobody hears a scream in the dark, did it happen? Or, If nobody sees a planet, does it exist? Many "complex" people answer no. Sheesh, if that were correct, you couldn't even ask the stupid question. This comes close to the stupid question Is the moon made of green cheese (instead of moon rock) if you choose to believe that it is? Many "complex" people answer yes. I ask, how can they believe in anything if they do not even believe in Truth? Since the vast majority of them say they believe in God, I ask how they can, since they can create and discreate him at will?
Such illogical, irrational and conflicting beliefs crash your brain if you don't keep them segregated into different halves of the brain and then keep one half of it shut down. Doing that is called compartmentalizing.
This is the predicament narcissists are permanently in. Since they identify with their phony image reflected in mirrors, if their mirrors abandon them, they feel that their very existence is snuffed out! The fate worse than death.
Now, a normal person may feel buried alive by total abandonment. But even in that hell, he will say, "I think, therefore I am."