A friend of mine was baffled that he wasn't getting promoted. He was getting his work done and coming up with good ideas. But people who were less capable seemed to be progressing faster.
"It's just stupid politics and unfairness", he grumbled.
When the world doesn't seem to operate according to our expectations, guess where the problem is?
Yeah, you got it...the expectations.
When your model of the situation, and therefore your expectations, doesn't capture some key variables or dimensions, the course of events will baffle and frustrate you.
In my friend's case, his model of the world derived from school where studying hard and doing well on your tests gets you good grades. But in the corporate world, it isn't that one-dimensional or clear-cut. Collaboration, enthusiasm, likability, influence, working on the right things, producing and demonstrating results, etc. matter in both promotions and impact.
When things don't go as expected, instead of being annoyed at the unfairness, figure out which dimension you may be missing.