because there's nothing else you can do besides die. and if nothing matters, and death is the end, then what's the difference if you die sooner or later? if there IS no difference, then asking "why should we live" is the same as asking "why shouldn't we live"

it's a matter of choice i guess, nobody's answer will be the same. after birth, it's essentially up to you to make the distinction between "there's no point to this, i think i'll die" and "i'm going to die anyway, so let's die doing something worth dying for".

and i'd say the only thing worth dying for...is living.