Imagine one day you were to come across a young man digging a hole in the earth with a shovel. An inquiry into his actions leads to the conclusion that he is digging his grave. Likely you would find this intriguing, and would attempt to draw more information from the man. Suppose the man explained that he wanted the best grave he could create throughout the years of his existence. The man is literally spending his life preparing the resting place for his dead body.
Would you find this ridiculous?
Yet, throughout human existance, like the man digging his own grave, we have spent our lives preparing for our death. Many find it necessary to believe in an afterlife, and are willing to sacrifice parts of their earthly lives in order to gain admittance. Others spend their lives researching various religions, sciences, and beliefs, in order to find something regarding death that they can come to terms with.
At the very root of it, everything in our existence has grown out of our obsession of death. Humans fear death so much that we have created religion, (a way to either accept death with the hope of some sort of better life,) and science, (a way of postponing death through medicine, or other forms of preservation.)
Why?
Why can't human's just accept that this may be the one and only life we have, and live it accordingly? Yes, we are afraid of what happens after we die, afraid that there may be no purpose for our existence. But why allow that fear to dictate the way we live the life that we know for certain we have at this moment?
Why can't we spend our lives simply enjoying being alive?