You don't need to know all of your answers in advance to solve a problem or to reach your goal. But you must have a clear idea of the problem or the goal you want to reach in advance.
Everyone who achieved success in a great venture, solved their problems as they came to them. They helped themselves. And they were helped through powers known and unknown to them at the time they set out on their voyage. They kept going regardless of the obstacles they met.
Don't procrastinate when faced with a difficult problem. Break your problem into parts, and handle one part at a time. All you have to do is know where you're going. The answers will come to you of their own accord.
It's the job you never start that takes longest to finish.