To effectively teach or pass on knowledge, understanding is the most important requirement for a teacher. You cannot teach electrical engineering without comprehending physics, digital electronics, etc. Parroting terms in electrical engineering makes one look impressive but not effective, if one does not grasp its meaning.
Effective journalists have to put in effort in understanding their material thoroughly. If they cannot internalize and completely perceive their material, they may not transfer it well to their readers. You cannot tell a story if you do not know the whole story. Details give away whether a writer really knows what he is talking about.
Parrots give empty words because they did not receive understanding. Parrots cannot explain their answer. They do not understand adequately, but just enough to make them look smart. They do not give comprehensive answers when directly confronted. A parrot keeps blabbering whether those who hear understand or not.
Effective teachers absorb the concepts and ideas for the topics they are to teach. These who impart wisdom have a level of appreciation for their topic, a thousand times that of a parrot appreciating a word. Imparting also considers hostile resistance, as those who understand are more gentle towards those who unfortunately are ignorant.
Great teachers question why their students may have difficulty understanding. Unlike parrots, teachers probe why students aren’t learning.