I never studied psychology. Haven't read Freud. But I managed to come up with a diagnosis, all on my own, that matches his clinical diagnosis of psychological projection.
Psychological projection was conceptualized by Sigmund Freud in the 1890s as a defense mechanism in which a person unconsciously rejects his or her own unacceptable attributes by ascribing them to objects or persons in the outside world. For example, a person who is rude may accuse other people of being rude.
It has long been my observation that the thing that many people complain of most in other people, is the thing that they are most often and egregiously guilty of. The bad driver complains of every one else's driving habits. The person who monopolizes every conversation complains about someone else talking too much. The really bad mother complains about someone else's parenting skills. The one who complains that people are always yelling at and threatening them is the one most likely to erupt in harangues against someone else.