Complaining can be cathartic in the moment, but does it get you closer to change? Does it actually do any good?
It might do just the opposite because you are focusing on the negative.
If there is a problem with an action associated with it (that you do or commit to taking), that’s simply important.
But if it is something negative about another person or situation and you have no power to change, try letting go. To let go you first must notice. How often do you complain? And can you stop yourself.