Decision theory teaches me that I can practice better assessment of options using reason, and getting outside of the box of my own presumptions and assumptions.
Learn to clear away the fog of your presumptions and reactions.
Also learn ways to simply get out of those—other voices, other opinions.
Develop the habit of not presuming you know.
My point here is that this is different from “creating the reality you want to create”. It is easy to conflate the two, thinking that any time you can reasonably predict a negative outcome, you are simply biasing yourself towards a bad outcome. This, however, can be very hazardous. It means that your positivity points you in the direction of denialism, and is likely destined to eat you, at various points.
I think people are afraid to look at the data, because it might color their presumptions, and those presumptions might in turn color the outcomes of their creations.
And I do believe that what we believe has an influence on what happens. But what are those relationships? If I believe I can fly, I still cannot fly by flapping my wings. That is generally demonstrable, and if that were my project, I might want to reflect on it.
It is far more valuable to have a grounded understanding of what is possible and not possible, and move from this. This can lead to tremendous mistakes.