There is a saying in ninjutsu "Banpen Fugyō" or "Ten thousand changes, no surprises". It is related to expressions of mushin, munen muso - a lot of Japanese!
But what does it all mean? Mushin means not having a fixed idea on how to respond, being spontaneous in the moment. Munen muso means 'no desire, no thought' very similar to mushin. This is also needed to pass the sakki test by the way!
With Banpen Fugyō the central idea is that no matter what happens you do not loose your mental and emotional balance, or lose a calm analytical mind. When confronted with angry opponents, seeing distressing scenes or experiencing loss - or joy, you can retain an objective view of what is really happening behind all the noise. Sounds great, but how does one do that?
First step is to develop a perspective that its never personal. No matter what, in a conflict, its not personal. They are just making noises that are an expression of their frustrations, they are trying to goad you into that physical conflict as they cannot express there emotional state any other way. If you respond with emotion, or physical action you are giving them what they want, feeding their ego and need for conflict. Why would you do that? Instead of reacting to their invitation for conflict it would be better to ask why do they feel that way?
The same applies to observing being cut off in traffic, seeing a person or object which feels offensive to you. In these situations it is much better to acknowledge that you feel upset by whatever it is, but actually it doesn't affect you, your family or your ability to provide for yourself and family - so there is no need to react.
The more subjective the irritation the weaker you are. If you get angry and emotional at a persons appearance, at a vehicles colour or at another objects appearance, you can be manipulated. If you can be manipulated easily, you can be defeated easily.
Develop a sense of detachment from irritations - we all have them, its just how you react that matters. Banpen Fugyō means that you will face trials and changes and be able to judge them subjectively. This means it is less easy to be manipulated and goaded into an unwise action. The reverse of this is that you can develop a way to manipulate an opponent and thereby avoid physical conflict, to create opportunities to escape, or ultimately to defeat them.
You are only as strong as that which angers you....