If you've ever said to yourself, "I knew this would happen," what were the circumstances? Were you ecstatic about the way things turned out, or disappointed? How did you know it would happen?
You can always choose a feeling of knowing about any subject matter. You can choose to know you will get the job just as easily as not. You can choose to know your product launch will be a success. You can choose to know that person loves you.
Some things are easier to know because you don't have resistance to them. You know you will succeed because you have in the past. Try introducing that sense of knowing to the aspects of your life where you have a seed of doubt. When you try something, tell yourself you will succeed, and never waiver from that knowing. Never let yourself tell you otherwise.
With practice, you will realize that every time you truly knew--without a shadow of a doubt--that it would turn out a certain way, it did.