The Quest

Imagine you're standing on a train while your friend is standing outside the train, watching it pass by. If lightning struck on both ends of the train, your friend would see both bolts of lightning strike at the same time. But on the train, you are closer to the bolt of lightning that the train is moving toward.

Now imagine if that train is your life, the bolt of lightning hitting behind the train is the day you were born, the one you are inevitably moving toward is your death. Can you guess what your friend represents ?