I agree that beliefs can be chosen and it can shape your lives.
However, I think we have to think within certain confines, like, I don't believe I can fly without use of aids, but I believe if I want to fly, I WILL have the wisdom to pursuit the right knowledge, find the right physical means..etc. to achieve my goal.
I guess it is similar to asking the RIGHT question for divination.
eg. when you are in physical danger, " I believe that I can over come this " vs " I believe the danger is not real ", the former definitely is more wise than the second!