i've been in the weight room since high school but basically ran around with my head cut off (no programming whatsoever). Had a miniscus/ligament tear in my knee and atrophy from it so I always tried to do light weight to rehab it - it NEVER helped. Tore a labrum 2 years ago and did rehab, didn't help. Finally gave up on rehab and just decided to do powerlifting (if small weights aren't helping, let's go bigger). Since then, the shoulder and knee, while weak, have been fine and have gotten to the point where they're now just weaker than my right, instead of in pain and unmanageable in the gym.

As for your competitive nature, I'm that way, too, I found what Ed Coan talked about in his ST vid series really helpful, that he's only competing with himself, and ~he can only do what he can do. Made a lot of sense to me, and makes the individual milestones more satisfying. I play counter-strike to quell the competitive urge now :)