I had a moment in my 20s where I just stopped and thought, "Every single ancestor I had from my parents back to algae had offspring. What if I don't?"
If you consider the whole Ocean as history, and the present moment as a single solitary wave heading towards the shore, and your life as the surfer on that wave, it doesn't matter what came before you. What matters is the wave. You get to ride it and wipe out. And that's it. I don't care if that wave is a composite of a million unknown ripples in the cast Ocean. It doesn't matter really.