Hurt and healing

I've done some very stupid things and hurt myself physically in the last 22 years. Pain that accompanies these injuries have taught me to appreciate the value of good health. It is the healing process though that has really amazed me. The body heals itself through a series of pre-determined processes.
But what about emotional trauma? Does the body/mind have a set process by which it goes about repairing the pain?
Is pain a part of the growing up process? This heaviness in the heart is disconcerting.
I saw a movie recently, where the heart is described as a muscle and analogous to going to the gym, is the process of going through mental trauma. The heart grows.. stronger. It is fitter for the next time around.
No pain, no gain.. eh.