I'm not sure what your asking exactly - do you mean at the moment we're thinking of death we might not be able to live life to the full, or that knowing generally that death exists might prevent us living life to the full? In my case, as I grow older, I am aware that my span of time is running lower and lower - my response is to try to live a fully as possible - to maximize the time I do have. I certainly don't have time to go about moping about death. Maybe in a few years, life extension will become a real medical possibility - retardation of the ageing processes - until then, better make the most of it all.
If we didn't die, we would never think about "living life to its fullest" Death makes the very idea possible.
no, i think that thinking about dying, about being cognizant of our mortality, if anything distracts and distorts and prevents a lot of what we might otherwise do. i don't mean by that that there is any advantage in living carelessly, or seeking risk, but rather the greatest enjoyment of what is sane and cautious even, does not come when it is overshadowed by how limited a time in which we have to do so. (nothing wastes time more then being in a hurry. and nothing prompts people to be in a hurry more then the realization of how limited is the time that they have.) =^^= .../\...
maintaining an awareness that i will someday leave this place, that i will not always be me, in this body, makes me feel more alive and in the present than most things.