My wife tells me that she once heard a teacher's goal is not to teach until someone understands, but to teach until there is no possibility of misunderstanding.
Unfortunately, sometimes when we think we are teaching something very clearly, we find we actually are not. Take my son-in-law, for example. He worked very hard to teach his little daughter to say DaDa. He did a great job! She learned the word, she's just a little confused as to the meaning.
May we all try to communicate clearly and well, whether we are talking about real estate, or discussing who is who.