Why do humans have the natural instinct to think about the meaning of life?

"I think, therefore I am." Humans are self-aware we have hindsight, foresight and recognize our present state. The question evolved over time and become more complex as we find out more about the human past, both factual and mythical.

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For some people, it is a matter of faith. The greater question of why we live, and in fact why humans are alive, is not one we can answer, even after decades of scientific investigation into how Earth and its life arrived at this point. The religions of the world each have an answer, but some will still question whether all that has occurred, and will occur, is part of the grand scheme of Creation. When we think outside of our own lives, about what will happen billions of years from now, it is natural to wonder what the purpose and the fate of humankind is meant to be.