I guess there are people who really believe that reality is malleable and if you say something often enough it becomes "true", as O'Brien explains in 1984:

"I tell you, Winston, that reality is not external. Reality exists in the human mind, and nowhere else. Not in the individual mind, which can make mistakes, and in any case soon perishes: only in the mind of the Party, which is collective and immortal. Whatever the Party holds to be the truth, is truth."