Best we can do is tell others how we feel,
then try to negotiate and collaborate on a mutually beneficial assessment.
Do you have a valid complaint?
Do we have a fair point to make?
Did the other person act in a manner that is selfish or, worse, abusive?
If we are unsure, we should offer our perspective and ask them to explain themselves.
If they refuse to do so, then we may have just confirmed our suspicion.
We always deserve to know someone else's intention when they interact with us.
And if they refuse to answer our civil inquiries, then we have the right to leave the interaction
and not return until they are willing to explain the origin of their action or statement
(or inaction or silence as the case may be).
The Feeling Valid? section
has more information to help you determine when a complaint is in order.
Remember, if you cannot justify your feeling, you do not have the basis for making
your discomfort someone else's responsibility.