The latest research suggests that this way of thinking actually harms you. In the book Rethinking Positive Thinking: Inside the New Science of Motivation by Gabriele Oettingen, we are told that the research calls for balance between positive thinking and the potential negatives. Quit with fantasy thinking and engage in reality which looks at both the good and bad for achieving what you want. Balance leads to more success.
Be a realist, be a pragmatist, and do not believe that willing what you want will get it. Thoughts of money management success has to be tempered with the fact that there is just a lot of hard work and failure with running money and making forecasts.