Causality shapes the way we understand the world, and the way we structure much of our knowledge. We start early to ask 'why' questions, and the urge to find causal explanations continues to be strong throughout life. When observation fails to provide them we often invent them, and we may even invent entirely false memories to support them—all entirely unconsciously, of course. Memory is anything but the mental video recording we tend to imagine it to be: research has shown that we re-create our past every time we recall it, often slightly differently. And our behaviour is not controlled as much by the conscious, rational part of our brain as we usually assume. Our unconscious mind determines much more of our behaviour than most of us like to believe-it does well over 90% of our thinking, according to recent research. Sometimes our unconscious mind reinforces our conscious mind and sometimes it overrides it. It gives us intuitions that, research shows, are often remarkably accurate, gives experts abilities that they are unable to explain, and makes most of us avoid doing things we know we should.