Flexing the right muscles

I was discussing muscle development and atrophy of sorts with a friend of mine some time ago. "Worry muscles" could become over-developed from constant practice, as "faith muscles" might atrophy from lack of use. Hours worrying over things that are out of one's hands, occasionally leading to anxiety attacks, could only cause the worry muscles to grow stronger. It occured to me that those anxiety attacks are like cramps that we suffer when certain muscles become overused: they overheat. Worse, overusing those worry muscles causes the opposing muscles to shrink and go to flab. It occured to me that this applies to me. I would overuse my "temper muscles" sometimes to the point of apoplexy. God knows that temper is part of human nature, but Christ cautions us even against anger. Why? Because while becoming angry is an emotional response, staying angry is a conscious decision that we unfortunately make occasionally. By staying angry, turning over the cause of anger over and over in my mind, I feed the fire. This often results in hurt feelings when it boils over -- quite often not my own. It is silly of me to ask the Lord in prayer to grant me more patience and an even temper, if I choose to overuse those miserable temper muscles. It is actually my choice whether or not to remain angry, risking the prolonging and even propagation of misery around me. As I told my friend, use of the undesirable muscles should be avoided. For me, when the occasion comes up to get angry, I must immediately crush the bitter and resentful thoughts that come with that in order to avoid feeding the fire. It's easier said than done, of course, but God would count every effort we make, not just the successes. Thankfully, if we exercise the "self-control muscles" often, we can expect them to be strengthened, causing my "self-indulgent muscles" to hopefully shrivel up to minuteness. SO what does this have to do with Christian Unity? Not much, really, but this is a topic close to my heart because my temper has been my cross for years. On the other hand.. has anyone ever heard of what causes "Christian Unity muscles" to atrophy?