Chogyam Trungpa said that
irritation is the vanguard of basic goodness, or so I've heard from some of his students. In standard English, this means that when you find yourself irritable, you should stick with the feeling and not try to escape it by badmouthing your situation. If you you can be present with the raw feeling, without stories and justifications, you may be rewarded with an experience of the mind and the heart opening. You might see something beautiful... human... maybe even sacred.
I've had this experience a few times, where I'm walking down the street, trying to shake a negative emotion, hearing the story in my mind, and then something wakes me up. I see the bigger picture all of a sudden. Sometimes I have to laugh. Other times, I just shake my head in wonder. Unfortunately, there are many more times when I don't wake up and the negative emotion leads to complaints, stories, unnecessary conflicts.
We all get irritated and we all complain. We complain about traffic, about work, about our friends, about our lack of a friends... it seems like there is always something to complain about, even if it never solves anything.