Its due to that swirling mass of guts and blood that you're able to ponder on such questions...most miraculous things can be both beautiful AND unpleasant; birth, sex, death...life itself.

Death will always be of fascination to us because we're alive - its difficult to come to terms with a state so unimaginable to the one we're in presently. A degree of interest is healthy - but when thoughts become obsessive it's an indication that we need to reevaluate our priorities. The bottom line is that life is for living - it's not in the amount of things you do, the number of achievements or even the understanding gained but the quality of all the above. We can't choose how we die but we can choose how to live.

You're young and you're bound to question; so do so, but most of all just enjoy what you can and be thankful for the happiness that comes your way.