Are you lying to yourself?
When you keep making up excuses for your failure to the point where you are so convinced by your own lies you no longer make an effort to seek the truth, you will think you are fine while you actually suck--and you will stay that way because you see no reason to improve yourself anymore.
Those who are motivated to learn and improve are never satisfied with where they are at. They will always see imperfection in their work and ask themselves the question, "is there a better way to do this?"
Good dog trainers are always learning no matter how much they have already achieved; while many owners with bad dogs spend their time and energy making excuses: "my dog is so protective!" "O he is just jealous!" "she is aggressive because she was abused before."