I was injured on my first workout (after I finished the indoctrination phase). I recovered then injured myself again shortly thereafter. I'm ex-US Army Airborne Infantry, meaning I didn't get up off the sofa after a lifetime of little activity and start "ripping". I'm no stranger to physical activities that can seriously hurt you.

I eventually found a strength training program and learned just how poor my form was for many exercises. Thankfully I'm doing great now and growing stronger.

EDIT: Words