First of all, that is it. It's small and insignificant, and so are we. Atheism brings the realisation that we have one, pathetically short life, then we die, and all of our knowledge, our memories, our feelings, our personalities and everything that makes us us disappears, and all we become is a lifeless corpse like any other. That's why it's so important to spread it around. Imagine if Socrates or Hawking or Einstein thought these thoughts then died without telling anyone. Lives wasted. The only way any part of us can exist forever is to really make a mark on society.