I've been thinking about the idea of being "dead inside" and I don't think it's a good fit. If people are anything like me - someone you could definitely describe that way - they have an unstable cocktail of emotions stirring around at any moment. What creates the illusion of being "dead" is that we have throughout our entire lives been trained to never express them. Even if we think emotions are when you cry or rage or whatever, that's just how you would normally act on it. The underlying feelings are still there to create suffering and guide our behavior. If we have a "dead" reaction to something big, it might as well be that we are too drained to absorb more ingredients into the cocktail.