Because maybe you do but that you never truly paid attention! That's why I'm not into the "positive affirmations" concept; rather the "positive confirmations" from our history that we'd find, in all likelihood, should we look closer! Our self-talk doesn't have to be a bully... It's not even us! It's the limiting beliefs that were vehiculated to us by someone else; it's someone's else voice, and guess what? We can always destroy it! The program is reversible but it requires some humility, honesty, openness, consistency, patience, and tons of courage!