Mistake #1: [Blind] Conformity and Instability
…such that a person is a follower of others without thinking: if they do good, he will do good, and if they do wrong, he will do wrong.
Mistake #2: Extremism or Idealism
…such that you find the person dealing with matters as being either true or false, so there is no middle [ground for him]. And he sees things in in two colors: white or black.
This is extremism and idealism, for indeed there are among colors: red, grey, yellow, and green–not just black and white.
Mistake #3: Generalizing Opinions
…such that by just seeing you in [one] error, he generalizes [his] opinion about you in everything, and the same goes for his views towards things and matters.
Mistake #4: Not Recognizing [a Person’s] Specialization [in a Field]
…such that he [himself] knows everything and is good at giving an opinion, speaking about, and doing everything. So he is an electrician, a plumber, a car mechanic, a psychologist, and a doctor, and he does not acknowledge other [people] than himself.
May Allāh have mercy on a person who knows his own worth.