Isn't the meaning of life really the meaning of lives, and hence particular to each life? There is no single "life" as it were... thus, we decide on the meaning of our individual lives... the meaning of my life is 'x':
A super-devoted mother says the meaning of her life is raising her kids...
A neuroscientist says it's to discover how consciousness develops from neuronal activity (or if not, how it does at all)...
An Olympic-level sprinter says it's to run faster and faster, to reach the peak of his physical abilities and know himself, his limits, his humanity, better through that...
A priest says the meaning of his life is to minister to God's people...
And who are we to argue with these and other folks with distinct ideas about the meanings of their lives?
For those who don't know, maybe the meaning of their lives is to discover some absolute meaning of life, or barring that, to simply live life... or maybe there is no meaning for them.
I guess I'm basically saying I think the meaning of one's life is what one decides it is.