If it's any help, not one of us is perfect. Do you know what happens when you get better at each exercise? You become more acutely aware of everything you're doing wrong. When I do a set of squats, my inner dialogue goes something like this: "too much weight on your right side, put more weight on your left side; you just over-corrected, bring it back to central; yay, this rep's not fugly!; your weight shifted forward, drive through your heels; I said heels, not toes!; knees out, dammit!; chest up, up-up-up-up-UP!; glutes!; knees and knees!; too much weight on your right side again!"