" Envy occurs most commonly and painfully among friends. We assume that something in the course of the relationship caused the friend to turn against us. Sometimes all we experience is the betrayal, the sabotage, the ugly criticisms they throw at us, and we never understand the underlying envy that inspired these actions. What we need to grasp is something paradoxical: people who feel envy in the first place are often motivated to become our friends. "
― Robert Greene , The Laws of Human Nature