To create your own meaning, if nothing else. The influence of our existence upon the universe in which we live, as it currently stands, is quite minimal. A mass extinction event could occur and decimate all the life on this planet, and realistically, very little would change outside of the environment we're currently restricted to. Some might call this perspective depressing, but i'd call it liberating. You can do whatever you please with the life you're given while you're here. Some paths may be more difficult than others, and every action has some form of consequence, but it's still a grand world to explore. And for better or for worse, at least you can say that you lived.