It’s important to know when you’re angry and at whom. This gives you the option of choosing whether or not to express your irritation openly. In a political situation (such as dealing with your boss or a policeman), where the consequences of open expression of anger seem to costly, you may decide to keep your mouth shut. But you need not feel stuck with your unspoken resentment. Instead, you can tell someone you trust about how frustrating it feels to be mistreated by people too dangerous to take on by fighting back directly.
In personal relationships, it will serve you better not to let irritation accumulate. In the long run, your suppressed feelings will make themselves felt by your withdrawal from someone you care about or by some later unintended, exaggerated outburst. Even with people who matter personally, you don’t always need to counterattack what you experience as abuse. Instead, you can talk with them about how awful it feels to be angry with someone you love.
At times building walls between people is necessary, but building bridges feels better.