I look at the universe and how incredibly vast it is and how insignificantly small we are and it makes me wonder how completely irrelevant life is. If humanity were to die out tomorrow, the universe would not care. The world would not care. Everything would go on as though we never even existed. It seems to me that everything we deem important is only so because we need it to be, not because it actually is.
To me, we're just a bunch of apes on a rock flying through space trying to get by as best we can and for me, I figure I might as well enjoy myself while I'm here =)