I loved the cartoon angry kid b/c it's so twisted.
http://www.angrykid.com/main.html
There is also an appreciation for this character due to the metaphor. As much as I pride myself on being a nice person, I can get mad. Getting mad is okay b/c it's an indication that something is not right.
It's then my duty to focus and fix the problem. With people, it's all about removing myself from unpleasant situations. With work, it's all about figuring out how I can resolve the problems. Take today, the accounting department's computers were all down. It took me a while to track down our consultants and fix it, but it's fixed. Now we are having VM issues, and I am once again tracking down the vendor to come take care of it.
I was angry today because I did not sign up to be the IT person, but I inherited this duty when the prior non-IT-but-do-IT person quit. As much as I pride on being capable, this is not how I envision my career. I do miss being at a well-staffed company where the problems are solved by competent people.
So even though a lot of people say don't get mad, I encourage anger. It's what you do with the anger that is important. Anger should be the motivation to change and not lead to frustration. One must not give up at the sign of challenge but to always have faith that the solution is up to us.