This repeats some of what was said above, maybe it will spark ideas, or not.
Many things have purpose: pigs and chickens, bacteria and yeast, cars and sunglasses. The dead things are subject to laws of matter, nothing more, but why do the living things choose to do what they do? We put microbes in the warm environment they enjoy, serving our purpose, but even after you have eaten that fat pig and taken your own life out of serious depression, those little bacteria seem to think being alive is a great idea and are more than happy to utilize all that energy you have consumed to help themselves to being alive.
So why do they? Are we content to believe bacteria understand a deep and rich tapestry of meaning, while we fail to see the purpose of it all? Surely, we are the brighter of the two.
We may have a purpose for something larger, but not for ourselves. Neither thing is what keeps us going. The universe has a purpose for us, we are here to accelerate entropy, we are destroying ourselves, like yeast in the oven, but not before we complete the task and if we are lucky, all get eaten. In the truly big scheme of things, our years are so many minutes on an oven dial. Not real inspiring or meaningful, yet we trudge on.
Well... that is, if the universe has an actual boundary (which there can never be evidence of). Why would the universe (all known existence) just want to speed up entropy and destroy itself, as soon as possible. Seems a noble task, if you think of it like wanting to sleep, possibly be reborn, to be left alone, to be without pain. Not because it lacks any real purpose. But being dead then does not quench anything.
Viewing ourselves, we see that we do not control whether or not we are alive, we are born without any choice in the matter, and we get put in an environment with these maniacs, for whatever other purpose, that is not easily known. I am simply curious, why I would say revenge is one purpose of my whole life. In so much, as I want to feel like I have a choice. I want my choice to affect something larger than me. I want to know what that larger something is, what its purpose for me is, and how much control I have, and why it wants me alive or dead, because it doesn't feel like I have any control. Even if I could know, it doesn't feel like I can, I might turn out to be my own worse enemy. I may find out I am being kept alive for some evil, myself.
The purpose of doing work or creating work, to stay alive... and to hell with whatever the bigger picture may or may not be. This kind of purpose is directed inward, toward solving a problem like boredom, which can end up killing you, or protecting your skin from herpes or something. The work then has a purpose to simply keep us alive and comfortable. To keep our family unit alive. Simply being alive is very rewarding, in my opinion. This goes beyond simply existing, it goes into exploration and having those moments of joy that you experience by waiting around for them.
You don't need to be a human to experience being around, you could just be a brick. They exist, probably pretty cool... being a brick, to have no purpose of life beyond being a brick... or in a vegetative state. A brick being "dead" doesn't see the point of "living" either, maybe something else saw the point of it being dead, which was likely a human accomplishment, really, probably some forest fire we started 50,000 years ago. Then again, there is no particular reason that we became alive, for ourselves, in the meanwhile we think there is a purpose, and that is why we are still keeping ourselves alive... and why we are such useful little agents of destruction for whatever created us.
We have a purpose and nothing is going to a better job of telling itself it has a purpose than us. Kind of the reverse of what one might expect, or the inside out. There is almost a competition inside of me for finding purpose. With it I could acheive and control, without it I am wasting time and possibly being set up for some horrible death. What purpose am I fulfilling, in a survival sense, is a very vital question. I think the impulse for an irrational purpose comes out of nature and survival, and seeking our true purpose and convincing others they have a purpose is a really great for survival. Then the desire to "end it all" is just a gambit nature plays, which sometimes back-fires. After all, I seem to be accepting that life has no purpose, why should that even matter to us? Accepting that life doesn't have a purpose but deciding to go ahead anyway and hopefully eventually you will run into something unexpected. That's life, it is weird, but why would I want to kill myself? No purpose. Brick. All knowing, all powerful brick. You can just go on happily being a brick in all this chaos. The brick was... miniscule, unimportant, he found there was more to see, more important, intelligent, beautiful things out there than being a brick, and whether we actively choose to be "dead" or "alive" we stand a slightly better chance not to get eaten like a universal loaf of bread; so we create life.
There is definitely something going on. It doesn't matter how we got to this point... exactly, but we are now aware of a vast universe that we are not equipped to even explore. It is just crazy how much variety of how much stuff there is. If you want to call exploration a purpose, that is fine, I'll just hang around until something comes up, and dream secretly of revenge.