The human mind works in very strange ways. Once, for a Toastmasters public speaking meeting, I vehemently argued in favor of something really disagreed with. After I had given my speech, my opinion had changed completely, despite my argument being full of flaws.
As the wise old Charlie Munger says, when say or chant something, you're just embedding it deeper and deeper into your mind, one reason why he advocates the avoiding of politics by youth who lack the experience and critical thinking skills to evaluate the positions they take.