"You see, everything is about belief. Whatever we believe rules our existence, rules our life. The belief system we create is like a little box we put ourselves inside of; we cannot escape because we believe we cannot escape. That is our situation. Humans create their own boundaries, their own limitations. We say what is humanly possible, and what is not possible. Then just because we believe it, it becomes truth for us.
-- Don Miguel Ruiz in The Mastery of Love