I think about this, too. The whole idea of death is alien to me, because I have never known anything like it. How can I comprehend something I have never known? It's the fear of death that gets to me more. Because I think too much. Because I fear the unknown. Ugh, now I'm thinking about death again.
I'm totally with you there. In fact, it kind of even freaks me out when I think of relatives who have died since I was alive and able to comprehend that when they are dead they are gone and all that other deep crap. I mean, I had both an aunt and uncle who died from sickle cell and there are times I think about what has become of their existence. Yeah, they're gone but is everything gone? Is some essence or spark of their being just somewhere out there in the ether? Sounds silly I'm sure but it makes me even more uneasy to know there are people who are already in the "great beyond" whatever that happens to entail which just makes the point of wondering what will be when I finally go that much harder to wrap my head around.
As far as death is concerned, the only other thing that bothers me outside of what we've been discussing, is exactly how I will pass on. Preferrably, I don't want to be burned alive, drowned or hanged. :P