What's the point of everything? That's a pretty classic question, asked as long as people have existed, and I doubt there's ever really been a great answer to it. And the mere fact that it's been asked for all of human history probably means that the answer to my question is the same as it always has been: no more and no less so than anyone else's.
Our culture (and here I refer actually to the very specific subcultures I inhabit, thinking in no way that my experience is representative of any larger American gestalt) emphasizes the importance of certain types of achievement, either in one's career or one's social life (or ideally, both). One can be a doctor or a civil rights lawyer or a humanitarian, and directly and positively impact dozens, hundreds, thousands of lives. One can create art, and inspire and touch and motivate and provoke an audience. One can start a family, have a ton of friends, build a long and successful relationship, or spend every night and weekend in a glorious worship of Bacchus.
But what if one doesn't do very many of those things? What if one's career is relatively unimportant and unimpactful; if one has a very small social circle and interacts with that circle irregularly at best; if one has no children and no party life (but does, at least, have a partner to share important things with)?
I don't think that makes one (at this point, obviously: me) a failure, but it does create an empty feeling, a sense of pointlessness. Exacerbated by all the people on the planet, or even in my neighborhood, who seem to have a point.
But at such depths of self-pity, I begin to remember that the universe is billions of years old, that the Earth is just a few less billions of years old. That multicellular life on Earth has existed for a billion years, that humanity has existed for 200,000 years and that 175,000 of those years were the age of the neanderthals (all credits Wikipedia).
In other words, if I live to be 100 my entire lifetime, compared to that of the universe, will be roughly equivalent to 30 seconds of my own life. If the universe were a person, I would be born, grow up, live, love, learn and die all in less time than it takes that person to download a new episode of Weeds.
This is to say nothing of the billions of lives that have already been lived, and will be lived, by other humans on this earth. Which is in turn to say nothing of the potential billions more lives that have been lived by sentient beings on other worlds about which we know nothing. Which is itself nothing compared to the trillions of lives that have been lived by non-humans on this, and other, worlds.
In other words, my existence will be meaningless, no matter what I do. It will be over in the time it takes the universe to visit the bathroom, but with much less impact. And if that's the case, why does it matter what I do with my fantastically short time to exist? The best I could possibly do would still be utter insignificance, and futile emptiness, even if it might "feel" better. Likewise, the worst I could possibly do would still be insignificant (and so in a sense I have no free will, since I have no ability to impact the universe, but that's another discussion).
This might be a bit of a downer to someone else, but to me it's uplifting. The pressure's off. While it would still obviously be better to do something than nothing, to improve the planet for others in some way (rather than make it worse, or have no impact at all), the stakes are low. I'm not supposed to feel much different than I do, because all of our existences are empty, pointless and fleeting. That being the case, we should seek to enjoy our time as much as possible, to live in the moment (since we can live nowhere else) and to spend as little time as possible worrying about our significance, because we have none.