Our brains are great at social interaction and pattern matching, but terrible at reasoning about the complicated non-human systems which dominate our world. Abstraction is the adapter between the fearsome complexity of the universe and our simple primate minds; when the real world is too intricate for us to manipulate directly, abstraction gives us big friendly levers to pull instead. I’ll explain how this single powerful idea underlies computers, mathematics, language and everything else we rely on in our daily work as computer programmers, and then show you how to use it effectively.