When we say this, we might not be as accurate in our description of the situation as we believe.
Perhaps we mean, “that’s not what I was hoping for.”
Or we might mean, “if you knew how hard I worked, you would have made a different decision.”
Possibly, we mean, “if you understood the world the way I do, you’d agree that this outcome isn’t fair.”
We rarely complain about fairness when the world lines up the way we hope it will. Even (or especially) if the outcome was unfair to someone else.
There’s an enormous amount of unfairness all around us. People who don’t get the benefit of the doubt, advantages that are multiplied, systems that are rigged. But right here, right now, it’s possible that what just happened was fair, though it was also disappointing.