I find Kevin's final statement unpersuasive. To be human is to be aware of our own finitude, and to wonder at that. Montaigne argued that to philosophize is to learn how to die. Camus put it differently: men die and they are not happy. For me, this last thing is our first thing as humans. It is our defining characteristic, even though some animals may experience this in a different way.
And our ability to think about this casts us between angels and beasts. It is our reality. Facing it is our life's task.
Now, I've never really bought into this being-towards-death stuff. But I have to say, many times I wake up in the middle of the night, my heart pounding, with the dread thought: David Bowie can die. Facing that has been my life's task.