Well Slickback, think about your question.
"Life", as you called it, is independent of man. It exists outside of man. In other words, life happened, happens, and will happen without man.
If life did have a meaning or purpose (which I will now use), then man doesn't determine it, because life existed before man.
If life did have a purpose, and purpose can only be expressed by an agent, and since that agent cannot be man since life already existed before man came to existence, then it stands to reason that some other agent gave purpose to life.
Naturally, this agent cannot have been created, considering the fact that, again, to have been created means to have existed after life, not before it. To have existed after life means to be excluded from giving life purpose, since life happened before us miniscule humans ever decided what to make of it. So it stands that this agent must therefore be life itself (can anything live outside of life? This doesn't make sense). It creates life therefore it, not the arrogant ant that comes after it, decides what purpose is.
So you either believe that this eternal life-giving agent in whom there is life decides purpose, or you reject this and conclude that there is no purpose at all.
Obviously, I am not saying that man cannot and does not reserve the right to give himself purpose. This much is obvious and true. What I am saying is that man does not reserve the right to give life purpose; that simply wouldn't make any sense now would it?