An excerpt from The Little Book of Trading:
One final important gem from Larry Hite is that being wrong is okay. He says he was never very good in school and not much of an athlete either. But he turned that to his advantage because he was able to grasp the idea that he could be wrong. In fact, it came as no surprise to him when he was wrong. Hite recalls with pride: “I’ve always built in an assumption of wrongness [in my trading]. I always ask myself: What is the worst thing that can possibly happen in this scenario? Then I use that worst-case scenario as my baseline. I always want to know what I’m risking, and how much I can lose. And sometimes, when you really look at it, there’s really not all that much risk [which is why you can get rich].”
More on Hite.