This is from the book 'The Art of Thinking Clearly' By ‎Rolf Dobelli. Survivorship bias is a common logical error that distorts our understanding of the world. It happens when we assume that success tells the whole story and when we simply ignore the failures. For example if there are X winners and Y losers. We only hear the testimonies of the winners. Therefore, our conclusion is based on X winners, and we ignore the losers.