The central question of the meaning of life is: why live?
People clearly do live. So people clearly must have reasons for living, something causing them to get out of bed and to put one foot in front of the other. We can then ask the descriptive question and the normative question:
Descriptive: What are the actual reasons people have for getting out of bed and putting one foot in front of the other?
Normative: What reasons should people have for getting out of bed and putting one foot in front of the other?
The descriptive question is empirical, and as such requires survey data to answer. But the answers are so obvious that such data may not be needed. People live because: 1) they have an inner biological urge to live; 2) because the alternative, choosing to die, sounds horrible; 3) because they are curious about human history and want to bear witness to how things unfold; 4) because they have some kind of addiction and they can't wait to get their next fix; 5) because they have some kind of obsession or vision and feel compelled to work toward satisfying the obsession or realizing the vision; 6) because they feel excited and joyful about life due to their children, other family members, friends, or wider community who need and/or want them and make them feel welcomed, included, and like they belong; 7) because while they do not necessarily feel excited or joyful about life, they do feel morally obligated to live for the sake of those who want and/or need them to live, such as children or other family members and friends (or for the sake of some other perceived moral obligation); 8) because they feel excited by their religion and that they have a God-given purpose in life; 9) because while they do not necessarily feel excited by their religion or that they have a God-given purpose, they do feel obligated to live for religious reasons and that God would be wrathful toward them were they to reject their earthly life; 10) because their job and/or hobbies give them a sense of excitement and purpose; 11) because life is fun, exciting, dramatic, interesting, and so on, and being dead sounds really boring in comparison.
Certainly, everyone lives for some combination of the above reasons.
The next question is: should we be living for these reasons? Are these good reasons to live?
If the answer is no, and there are no objectively good reasons to live, and the choice to live is thus purely arbitrary, then life is absurd. Life is absurd when there are no truly good reasons to live and yet you live anyway as if there are truly good reasons to live.
If the choice to live is arbitrary, then there would be nothing wrong with flipping a coin and living if it comes up heads and choosing to die if it comes up tails. And yet we strongly feel that that would be an insane thing to do. We feel strongly that living for the above reasons is perfectly rational, details pending. Certainly, the smartest people in the world choose to live, and they choose to live for some combination of the above reasons. So if that combination of the above reasons is good for the smartest people in the world, why wouldn't they be good for you or me? (To refute this point you'd have to show that self-death is more common among the smartest humans, which, if I'm not mistaken, cannot be shown because it's not true. In fact, I wouldn't be surprised if self-death was more common among people who fail at life, and that life failure was more rare among the smartest people, and thus that self-death was less common among the smartest people. Though, there are likely conflicting factors. Smarter people might disproportionately feel higher pressure and expectations, causing despair.)
If you allow for objective reasons, and if you further grant that there are objectively good reasons to live, then life is not absurd, at least not for those for whom those objective reasons apply. Life is absurd for those who live and yet have no good reasons to live, or who have good reasons to live but better reasons to die.
People will say that "the absurd" refers to our demand for life to be meaningful, and life's subsequent failure to give us any meaning. The terms 'meaning' and 'meaningful' are vague, so let's put it this way: ..."the absurd" refers to our demand for reasons to live and life's subsequent failure to give us reasons to live.
But Camus also describes the absurdity of life as related to contradiction, juxtaposition, ridiculousness, and futility. At the heart of it, absurdity is the contradiction between life and death. Life commands us to live by letting us be born, and validates our existence. But then life contradicts itself and commands us to die and thereby invalidates our existence. With existence comes glory and with death, humiliation. Life conspires to both glorify and humiliate us. We naturally assume there is a good reason for our existence, only to discover that there really isn't. We naturally assume that there is a good reason for death, only to discover that there really isn't. Religion very nicely explains both the purpose of life and death (at least, Christianity nicely explains this, at least at first until you start questioning things and it all falls apart). But with the discovered falsity of all religions, we are left with an indifferent universe that couldn't care less whether you were born or whether you died. It turns out that our lives and deaths are purely the result of the chaos of random particles smashing together in ways governed by laws of nature that are there because they have to be because that's just the way things must be. Often, people die shortly after being born, accentuating the pointlessness and stupidity of it all. When life feels like one big joke, that's when you know you've encountered the apparent absurdity of life.
If the absurdity of life is a problem, then it is a psychological problem relating to a person's personal calculation over whether the reasons for them to live outweigh the reasons for them to not live. If a person calculates that they have overwhelmingly better reasons to live than not, then there is no problem. If a person calculates that they have roughly equal reasons to live and die, then they will struggle, even agonize, over the choice to live.
If you want to make the absurdity of life a philosophical problem, then you have to argue that because there are no objectively good reasons to live, everyone is failing to live on the basis of reason. Therefore, if someone wanted to live their life according to reason, which sounds like a very rational thing to want, then that person really shouldn't live their life at all. And yet they do. And it's this contradiction of living as if you have good reasons to live when objectively you do not that amounts to the philosophical problem of absurdity. But if we can argue that the reasons we live for are objectively good (which, we can), then the philosophical problem is solved. There is no contradiction.
On the other hand, if a person believes there are no objective reasons of any kind, then there are no objectively good reasons to live or not live (or do or not do anything), then this should result in a total paralysis of choice for the person who aims to live according to what reason says. Or, if this person says we needn't live according to what reason says, and instead must live according to what we want, then whether a person ought to choose to live or choose to die is incredibly simple: do whatever you want for whatever personal reasons you have, and there is no right or wrong answer. (And this, says the antirealist, is not meant to be taken as a command. If antirealism is true, there are no true moral commands. So as far as the antirealist is concerned, you may do whatever you want for whatever personal reasons you have, or you may choose to act contrary to your wants for whatever reason. Though, inevitably, everyone acts according to some desire of some kind.)
The person who insists that the absurdity of life is a real problem, they might have something like the following in mind. Consider the flip side to the central question of the meaning of life: why die?
For a person to choose to die they must be in the throes of some kind of despair. They must be pessimistic about their ability to maximize flourishing by living, and therefore believe that the next best thing, minimizing suffering, requires them to end their life. I've argued elsewhere that choosing death implies unbearable suffering. Unbearable suffering then, of one kind or another, explains why someone should choose to die rather than live.
We can divide the reasons to die, call them factors of despair, into three categories: broad factors, regional factors, and local factors.
Broad factors are those tragic facts about life that are deeply built into the nature of life. These problems can never be solved. The fact we live in a fundamentally neutral world, which is infinitely disappointing for the person who expected our world to be fundamentally good, is a broad factor of despair. So are factors pertaining to death, the imperfection of human nature, the inevitability of pain, ignorance, and so on. To be broadly pessimistic is to be skeptical about the goodness of reality as a whole.
Regional factors are those tragic facts about the lives of those around you. These are the tragic stories on the news, stories of horror, war, murder, and so on. They don't affect your life other than the fact that they give you an idea of the kind of world you live in, namely, a bad one, and thereby depress you. To be regionally pessimistic is to be skeptical about the goodness of the lives, or future lives, of other people.
Finally, local factors are those tragic facts about your own life. To be locally pessimistic is to be skeptical about the goodness of your life or future.
There is the goodness and badness of your life, the goodness and badness of the lives of those around you (in your family, city, country, or planet, depending on how far you zoom out), and, zooming all the way out, the goodness and badness of reality itself. There is the goodness or badness of these things in the short term, and in the long term.
The person who argues that the absurdity of life is an objective problem is saying that because we ought to be skeptical about the goodness of reality as a whole and about the goodness of our planet, this is cause for us to feel despair.
The distinction between broad, regional, and local factors of despair might not matter at all, because really there are only two things that matter: your psychology and your circumstances. If your circumstances are such that you are aware of the suffering of millions of people, and your psychology is such that you cannot ignore this suffering, then you will suffer too. If your circumstances are such that reality as a whole is tragic because everyone dies in the end, and your psychology is such that you cannot ignore the fundamental tragedy of life, then you will suffer. If your circumstances are such that you are suffering from poverty and disease, and your psychology is such that this bothers you, then you will suffer.
The question of absurdity then is whether we should be bothered by something we are not bothered by. If someone isn't bothered by the fundamental tragedy of life, and if they aren't bothered by the wretchedness of our world, and they only care about the details of their own life, then does that mean this person is irrational, or insensitive, or small minded?
I don't think so. If someone is locally optimistic while broadly and regionally pessimistic, then they can acknowledge the badness of reality and the badness of the world while acknowledging the goodness of the details of their life. Such a person can be rightly optimistic about their ability to flourish.
The worry is that a genuine truthseeker will be sensitive to the badness of reality and the badness of our world, and will thereby feel despair. We are rationally obligated to be depressed, says this line of thinking. You can only avoid despair by burying your head in the sand, by ignoring reality, and by living according to a noble lie.
But that's not right. If you zoom out, you will see a hopeless picture of walking corpses living on the edge of societal collapse in a world that will likely soon become uninhabitable on a planet that will eventually be destroyed in a universe that will eventually die, all part of a reality that is fundamentally indifferent to your suffering and absurd in its simultaneous insistence on your life and death.
I grant this, and to this extent I grant that pessimism is true.
But if you zoom in, you see people's faces and futures, fears and failures, pains and joys, laughter and life, and the many remaining days of their lives that they still have yet to live. You see the undeniable goodness of their happiness, the undeniable badness of their pain, and the undeniable superiority of their happiness over their pain, and thus the undeniable meaningfulness of making their lives better for the time being.
The truthseeker is sensitive to regional and global truths, but they are just as sensitive to local truths as well. Our experiences are undeniably real and true. Nothing is more real than pain.
So if a truthseeker lets the broad truths of life dominate their mind, they will come out deeply pessimistic and in despair. But if they let the local truths of life dominate their mind, they will find plenty of meaning both in terms of the flourishing to be maximized and the suffering to be minimized.
So the philosophical problem of absurdity returns to a psychological problem. If you find yourself living in the moment and being sensitive to local truths, letting the truth of the present dominate your mind, then broad factors of despair won't become local. But if you find yourself incapable of ignoring the broad truths of life, and you can't help but let the big picture dominate your mind, then broad pessimism will become local. You should be skeptical of your ability to flourish if your ability to flourish depends on your circumstances and your psychology, and your circumstances are such that you are living in an infinitely disappointing world and your psychology is such that you can't get over the fact that the world is infinitely disappointing.
People say that you shouldn't worry about those things beyond your control. If that's right, then local factors are all that really matter. But that's just the issue: if someone's psychology is such that they cannot help but have their minds dominated by broad truths, then that is a local fact. And so really there are only local factors of despair.
The problem of absurdity then is person-relative. It's no different than other local problems, like that of health, poverty, ignorance, stupidity, a lack of opportunities in life, and so on.
Most people's minds are, for obvious reasons, dominated by local factors, as that's what's right in front of them day to day, that's what their survival depends on, and that's what they can control. But I don't see how someone could be faulted for being highly sensitive to the broader facts of life. Practically speaking, they might be worse off, but if the person in question has local factors of despair anyway, then it's tempting to look toward life as a whole for some sign of hope. If it's despair all the way down, then the solution for this person is to choose death. But this will not apply to the vast majority of people, who are rightly locally optimistic.