Our culture doesn't give us a healthy structure for this way of living. Opinions and preferences are considered important ways to express our existence. They strengthen the ego, the false self. Its not that preferences are evil- its that we suffer when things don't go our way. Freedom is found in having an opinion, but fully accepting the outcome whether it jives with our opinions or not.
Complaining is used as a way of life, a form of social bonding. This unhealthy practice affirms the mindset that we know better then reality. If we constantly disagree with life, constantly complain, make critical and sarcastic remarks, we are out of harmony with reality. We cannot find peace when we fight the moment.
We have to be dilligent and whenever we feel frustration, strong tension or a sense of anxiousness or sad dragging or longing, we have to ask ourselves, "what am I resisting?". This simple practice becomes one of the most powerful and freeing of all!