"Keep this thought helpful when you feel a fit of anger coming on—it isn't manly to be enraged. Rather, kindness and civility are more human, and therefore manlier. A true man doesn't give way to hatred and annoyance, and such a person has strength, courage, and will—unlike the angry and complaining.
When we were kids the world orbited around us. We were incompetent and incapable, and very demanding. Some people carry the dogma that they are the center of everything into adulthood and can flip into a storm when reality doesn't match the expectations they had for a circumstance.