Have you ever told yourself no? I definitely have. I'm talking about thoughts like "Why bother applying? I doubt that school would ever accept me," or "This business idea isn't going to work. I'm too old/too young/too inexperienced". Or maybe "He'd never date me. I might as well move on." Or "My boss won't promote me anyway. Why should I even ask?" From what I can tell, we all doubt ourselves from time to time. The problem, of course, is that telling yourself no prevents you from getting started at all. When you decide not to act, you deny yourself opportunities. Once I realised this, I started following a simple little rule that has helped me stick to things and persevere when I normally would have given up. Here's how it works and why you should use it.