For example, suppose a complaining friend tells you, “I swear, my manager’s competence is an illusion.” That person doesn’t mean, “He’s a competent manager, but in a slightly different way than you might expect. In fact, he might even be more competent than you expect.” No, your friend means that his manager doesn’t have any competence. In the context of a metaphor, to call something an illusion is to deny every aspect of its existence.
