Thwack

You ever read something and then hear the whistling of an approaching clue-by-four? This is from Cassian's Institutes, Book 7 ("The Spirit of Anger"):

XVI. Sometimes, when we are overcome by pride or impatience and are unwilling to correct our unseemly and undisciplined behavior, we complain that we are in need of solitude, as if we would find the virtue of patience in a place where no one would bother us, and we excuse our negligence and the causes of our agitation by saying they stem not from our own impatience but from our brothers' faults. But, as long as we attribute our own wrongdoing to other people, we shall never be able to get near to patience and perfection

XVII. The sum total of our improvement and tranquility, then, must not be made to depend on someone else's willing, which will never be subject to our sway; it comes, rather, under our own power. And so our not getting angry must derive not from someone else's perfection but from our own virtue, which is achieved not by another person's patience but by our own forbearance. 

I don't consider myself a particularly angry person, but I know that when I do get upset, I tend to linger in it far longer than is right. In fact, if I'm being completely honest, I'll invent reasons to stay angry - imaginary conversations where I always have the upper-hand against whoever has wronged me. I'll spin out long, drawn-out, completely imaginary scenarios in support of whatever has made me upset.

It is true that there is a place for righteous anger. It is equally true that the greatest part of our anger is probably not, unless it be turned inward against our own failings. Even then we must temper it with certainty of God's mercy. No wonder at all that the prayer most commended to us is O God come to my assistance! Lord, make haste to help me!