If it is a person, ask yourself how you contributed to the situation. Usually you will find you did. You thought they ought to understand; you thought they ought to have known better; you thought they should have reacted differently. But if you are honest, you will realize that you did not use skills you had, out of laziness or complacency. Or ignorance: the corrective is study. I know how to deal with people, but I don’t always follow the rules I know. I think it ought to be easier. I shouldn’t have to treat them as if they are imbeciles, or lacking in balls, or constantly looking for a new pissing contest. But many people are. Why should it be easier? It is what it is, and I betray my own childishness in pretending otherwise. If I am failing to control what I can control, then I have no right to whine, and even if I am, it remains what it is, so I can ALWAYS control my reaction. None of us are truly helpless, even in the worst situations.
Literally every problem I have, or think I have, submits to this question. It is clarifying, purifying. The next time something or someone pisses you off, try it.