What advice did nicks dad give him

Nick is a young man from Minnesota who, after being educated at Yale moves to the suburbs of New York. Nick comes from an upper middle-class background (you had to have money to go to Yale, you still do!) .Nick is able to travel to New York and not immediately have to worry about money where as most people struggled to simply make ends meet. Nick's father tells him that if he holds men according to his own moral standards, he will misunderstand them,

"Whenever you feel like criticizing anyone, just remember that all the people in this world haven't had the advantages that you've had."