What is the meaning of human life, or of organic life altogether? To answer this question at all implies a religion. Is there any sense then, you ask, in putting it? I answer, the man who regards his own life and that of his fellow creatures as meaningless is not merely unfortunate but almost disqualified for life.
There is not one big cosmic meaning for all, there is only the meaning we each give to our life, an individual meaning, an individual plot, like an individual novel, a book for each person.