We are all susceptible to the pull of viral ideas. Like mass...

We are all susceptible to the pull of viral ideas. Like mass hysteria. Or a tune that gets into your head that you keep humming all day until you spread it to someone else. Jokes. Urban legends. Crackpot religions. Marxism. No matter how smart we get, there is always this deep irrational part that makes us potential hosts for self-replicating information.