Throughout my life I've struggled to find meaning. I've wondered, am I alone in this? I'd like to hear what others have to say. Particularly others that are more knowledgeable in philosophy.
Nobody knows anything. Philosophy is a fake study of subjective experience based on no evidence. Do what thou will. Anyone claiming knowledge about things they can't demonstrate is a conartist or sociopath.
More than fair odds, life is a random fluke of chance, and it has no meaning. Some people see this as depressing, but I see it as an opportunity to create the meaning you want in your life.
The most logical explanation would be to be able to acknowledge any of our potentially most barbaric desires or behaviors, and even go as far as to suffer to abstain from them, for a purpose outside of ourselves.
Self is the only thing we can be sure of, being selfless is possibly altruistic but could also be putting the only thing you can be sure of behind things that may not be important to ones being.
Not to say that being selfish is the way to be but giving all yourself away or keeping all for yourself are very unbalanced ways to get through the world, balancing the give and take of life is the path to living a peaceable life.
I suppose Marx's discussion on alienation is less about some ultimate meaning of life (which many people have already talked about here) and more about how people find meaning in their work, their humanity and the wider world, and how the way our society currently works alienates us from those things and from finding our own meaning, instead pushing us to act like cogs in a pointless machine. For example, if someone's waking hours are mostly spent making useless things for people they'll never meet, or denying people medical coverage, they're going to develop a very different sense of their meaningfulness than someone who builds houses in their neighbourhood, or who grows or prepares food for their family and friends. Both are labouring in order to survive, but the latter can see much clearer how their actions matter.
(I'm probably butchering it, this isn't a theory I know much about, so check to see if someone else has corrected me)
Given that religion exists I'd say you're not alone in seeking meaning.
There are parts of your brain that exist for the sole purpose of identifying why things happen, imagine the advantage an organism has that can spot patterns in their environment and make predictions based off of what they've seen.
Unfortunately sometimes that hard wired part of the brain seeks to find deeper meaning in places that provide no meaning.
Shadows don't exist, but we see them, they have no purpose because they are nothing but an emergent phenomenon.
An asteroid travels through space for millions and millions of miles in the depths of nothingness between galaxies. It is never seen by a sentient being and is far enough beyond the range of gravitational affect of everything that it's influence is less than a single decaying atom. Why is that asteroid there, what is its purpose? It exists to exist.
You are a bundle of atoms destined to lose cohesion, revel in the beauty of it.
What is it you seek? What is it you lack? It can be helpful to look into these questions carefully. It can also be helpful to take time to look at the exact moment-by-moment experience of this life that appears lacking. After years of philosophical study and years of trying to convince myself I wasn't dissatisfied, I stumbled upon Zen and found these kinds of investigations helpful.
I know nothing, but to me, there is "why," and there is "how." The why can never be proven and the how is fact. Religious institutions try to tell you "why" you are here, but they can not. They can only tell you why they think you are here.
In 1 billion years, there is a very good chance that we will not exist, so what's the point to any of this? Literally that. YOU are why any of this has a point. If you want to sit and stare at the stars, then that is why you are here. But then that is me telling you why you are here.
Why will always lead to how, which will lead to why, which will lead to how, that leads to why, then to how....ad infinitum.
From the movie "City slickers". The meaning of life is one thing. And that is whatever you are doing.
Just the thoughts you were wondering about, from a stranger in the wires.