We need to address the attitudes, perspectives and reactions we bring to situations and relationships because that is what brings anger, contributing to anger in ourselves and generating it in others. We can develop our tolerance 'muscles' just as we gradually grow accustomed to the cold as summer turns to fall.
Unfulfilled expectations are a frequent source of anger for me. I presume that people will do the job they were hired to do, companies will provide the services promised, products will work as designed. When these expectations are met with a disappointing reality an irrational rage bubbles over. A video from The Book of Life, "How Not to Be Angry All the Time" does a good job of explaining how optimism is tied to anger and yet the solution that it proposes is one I am unwilling to accept.
The other night I had a moment of clarity standing at the United Airlines lost baggage help desk. My son had a difficult time getting home from college for the holidays. With snow falling over half the country and a trip that routed him through both Chicago and Denver it didn't come as much of a surprise that his flights were cancelled and that his luggage was lost. As I watched people yell at the agent it made me want to never be one of those angry people again.