@ZipLine-- Socratic irony may play out that way but it doesn't have to. The person who poses the question or who requests an explanation does not have to reveal that he or she already knew about the subject. Often times this is not revealed. It is usually unintentionally revealed during a debate, especially if the purpose of socratic irony is to point out the faults in someone's argument.
Other times, socratic irony is used to make someone believe something or to make someone reveal what they would not otherwise. For example, a police officer may pretend not to know something in order to make someone talk during an interrogation or police visit. The officer will not reveal his knowledge in this situation. The goal is to cause the other side to think that the police is clueless so that they gather courage and accidentally give far more information than they had intended.