Montveil, you did hit it on the head. I changed the way I practice a couple years back as well...no more shooting 500 plus rounds every two weeks...now I shoot 2 to three times a week with much less ammo, maybe 30 to 50 rounds, and my intention is to do it all right, and hit my target every time, no matter what. I have to say it helped me a lot shooting less ammo more often, and I would get pretty tired trying to do everything exactly right after that many rounds, and develop bad habits from fatigue.
Your right on...nothing much matters without a center hit...first time you shoot...and every time you shoot.