The question of the meaning of life is perhaps one that we would rather not ask, for fear of the answer or lack thereof.
Still today, many people believe that we, humankind, are the creation of a supernatural entity called God, that God had an intelligent purpose in creating us, and that this intelligent purpose is "the meaning of life".
I do not propose to rehearse the well-worn arguments for and against the existence of God, and still less to take a side. But even if God exists, and even if He had an intelligent purpose in creating us, no one really knows what this purpose might be, or that it is especially meaningful.
The Second Law of Thermodynamics states that the entropy of a closed system—including the universe itself—increases up to the point at which equilibrium is reached, and God’s purpose in creating us, and, indeed, all of nature, might have been no more lofty than to catalyse this process much as soil organisms catalyse the decomposition of organic matter.
If our God-given purpose is to act as super-efficient heat dissipators, then having no purpose at all is better than having this sort of purpose—because it frees us to be the authors of our purpose or purposes and so to lead truly dignified and meaningful lives.
In fact, following this logic, having no purpose at all is better than having any kind of pre-determined purpose, even more traditional, uplifting ones such as serving God or improving our karma.
In short, even if God exists, and even if He had an intelligent purpose in creating us (and why should He have had?), we do not know what this purpose might be, and, whatever it might be, we would rather be able to do without it, or at least to ignore or discount it. For unless we can be free to become the authors of our own purpose or purposes, our lives may have, at worst, no purpose at all, and, at best, only some unfathomable and potentially trivial purpose that is not of our own choosing.
You or others might object that not to have a pre-determined purpose is, really, not to have any purpose at all. But this is to believe that for something to have a purpose, it must have been created with that particular purpose in mind, and, moreover, must still be serving that same original purpose.
Many Junes ago, I visited the vineyards of Châteauneuf-du-Pape in the South of France. One evening, I picked up a rounded stone called a galet which I took back to Oxford and put to good use as a book-end.
In the vineyards of Châteauneuf-du-Pape, these stones serve to capture the heat of the sun and release it back into the cool of the night, helping the grapes to ripen. Of course, these stones were not created with this or any other purpose in mind. Even if they had been created for a purpose, it would almost certainly not have been to make great wine or serve as book-ends.
That same evening over supper, I got my friends to blind taste a bottle of Bordeaux—an evil trick, given that we were in the Rhône. To disguise the bottle, I slipped it into one of a pair of socks. Unlike the galet, the sock had been created with a clear purpose in mind, albeit one very different from (although not strictly incompatible with) the one that it came to assume on that joyful evening.
Explanation:
Hope this helps! :P