What's the most resilient parasite? An Idea. A single idea from the human mind can build cities. An idea can transform the world and rewrite all the rules.
You know that nightmare you still have where you haven't studied all semester and you suddenly realize the test is today and you're doomed to flunk? You haven't been in school for years or decades, and you still have that dream where you feel guilty for not reading the textbook and not doing the homework?