carbinked, I'm so glad you're posted this. I've had the same feeling...or thought, or whatever it is. I've had such thoughts about myself and also about loved one (including pets). Not exactly a wonderful feeling/belief. I'm not sure of the cause of what you've described; I wish I knew. I think it could be PTSD - by that, I mean past trauma that pushed us so far beyond being able to cope that we felt that some part of us did die. Then that thought runs wild and becomes what you've described. Just one possibility.

I know, too, that believing that one is dead can be a psychotic symptom. It all just depends upon other beliefs, symptoms, ability to function, and so on.