We generally expect behavior from both ourselves and others that is in accordance with defined rules and standards (i.e., fair). Of course, this falls down a bit when the rules or standards are unclear.

Some behavior standards are unwritten just embedded in the culture.  Others are embedded in our personal value systems and might not synchronize completely with other people, although typically there is a fair amount of integration with our fellow humans.

Subjectivity

One of the greatest challenges in assessing the fairness of something, even when clear rules or laws exist, lies with the different possible interpretation of associated standards.

This leads to frequent situations where things one person thinks are justified and fair might not be perceived that way by others.   Resolving this problem in a reasonable and fair way is one of the main reasons for civil courts.

A Festering Wound

One of the greatest dangers about perceived unfairness is how it can grip you mercilessly, not letting go until you explode in agony. And, still, nothing is resolved.

Given others might not be sympathetic to your perceived slight, letting it continue unresolved leading to unsocial behavior only does you harm.

While the resolution, through discussion, open communication and understanding will not always lead to the result you desire, ergo the unfairness is not eliminated, at least your inner turmoil will be shut down.

If you believe yourself unfairly treated do not ignore it, nor lash out in anger but rather do yourself a favor and find a place where you can live with the situation, release any built-up angst and basically, move on.