But if you pat your own back, the good feeling will stay with you longer if you let it. You wouldn't keep scolding a friend for making a mistake or missing an opportunity, so don't do that to yourself. Forgive yourself for making a mistake. Then figure out what lesson you can learn, and use it to make better choices next time. Enjoy your successes.
Most people can remember the details of painful or embarrassing events that happened many years ago.
Keep that memory with you and think about it at least once a week. Set reasonable goals and meet them. If you do what you set out to do, you'll like yourself better. Meeting goals proves that you are in charge of yourself. Get to know yourself.