This line has been ringing in my head since I read the book. Mainly because I've always thought about it and it's nice to know that someone else thinks about it too.
"There will come a time when all of us are dead. All of us. There will come a time when there are no human beings remaining to remember that anyone ever existed or that our species ever did anything. There will be no one left to remember Aristotle or Cleopatra, let alone you. Everything that we did and built and wrote and thought and discovered will be forgotten and all of this will have been for naught. Maybe that time is coming soon and maybe it is millions of years away, but even if we survive the collapse of our sun, we will not survive forever. There was time before organisms experienced consciousness, and there will be time after. And if the inevitability of human oblivion worries you, I encourage you to ignore it. God knows that’s what everyone else does."
- The Fault in Our Stars, John Green