When you have acquired knowledge, there is a way to see if you have fully understood it or not. It is to explain it to others. Although you know something, if you cannot verbalize it, it is hard to say that you have learned it completely.
That is why the Jewish Havruta learning attracts much attention; this method has produced a lot of brilliant minds. The atmosphere of Jewish libraries is quite different from that of any other libraries where people are even careful not to make the sound of turning pages. In Havruta learning, people study and learn by heart, and then they sit face to face to discuss or to persuade each other. Through this process, they organize their thoughts and knowledge. They sometimes take notes on what seems important and speak enthusiastically with gestures and facial expressions.
The knowledge acquired in this way becomes completely theirs, and it is hardly forgotten. What is more, they get new information and wisdom from others during their conversation.
The Jewish learning method of seeing with eyes, writing with hands, and talking with mouth is far from a quiet atmosphere, but the effect is the best.