Knowing what irritates you and what really makes you angry is a useful life skill.
When you are able to take control and not be hijacked by destructive emotions you have more power over your life. For teachers this skill allows them to look at potentially harmful situations and respond calmly and effectively. The student causing the trouble may be unable to act well or unused to modifying their behaviour so the teacher can play a vital role here in modelling socially acceptable behaviour. Teachers have to be able to suppress their own emotional responses. The alternative is ugly.
Observing flight attendants I’m always amazed and impressed by how warm and friendly they are and was reminded of some research on the regulation of emotional expression as part of paid work : The Theory of Emotional Labour (Hochschild, 1983). The labour required to suppress emotional displays is considerable. The process of regulationg these displays requires acting and method acting at that, so there is congruence between the emotional display on the face and the verbal message.
Is it any wonder we teachers fall into an exhausted heap at the end of the day and delight in telling war stories and making each other laugh?