If our life is all we get to experience, then it's the only thing that matters. If the universe has no principles, the only principles relevant are the ones we decide on. If the universe has no purpose, then we get to dictate what its purpose is.
Humans will most certainly cease to exist at some point, but before we do, we get to explore ourselves and the world around us. We get to experience feelings. We get to experience food, books, sunrises, and being with each other.
The fact that we're even able to think about these things is already kind of incredible.
It's easy to think of ourselves as separated from everything, but this is not true. We are as much the universe as a neutron star or a black hole or a nebula. Even better, actually, we are its thinking and feeling part: the centre organs of the universe.
We are truly free in a universe-sized playground, so we might as well aim to be happy and to build some kind of utopia in the stars.
It's not as if we've found out everything there is to know We don't know why the rules of the universe are as they are, how life came into existence, what life is.
We have no idea what consciousness is or if we are alone in the universe. But we can try to find some answers.
There are billions of stars to visit, diseases to cure, people to help, happy feelings to be experienced, and video games to finish. There is so much to do.
So, wrapping up, you've probably used up a good chunk of the time available to you. If this is our one shot at life, there is no reason not to have fun and live as happy as possible.
Bonus points if you made the life of other people better. More bonus points if you help build a galactic human empire.
Do the things that make you feel good. You get to decide whatever this means for you.
Optimistic Nihilism - https://youtu.be/MBRqu0YOH14