Coincidences can make the everyday feel extraordinary. But are they magical, or just mathematical? On this week's Radio Replay, we explore our deep fascination with these moments of serendipity. New research suggests they reveal important things about how our minds work, and have a far more powerful effect on our lives than any of us imagine. We'll also explore the phenomenon of "implicit egotism" — the idea that we're drawn to people and things that remind us of ourselves.