These days, many people who are learning the Way listen to a talk on the dharma, and above all want their teacher to know that they have a correct understanding and want to give good replies. This is why the words they listen to go in one ear and out the other. They still lack bodhi-mind and remain self-centered.
First of all, forget your ego and listen quietly to what others say, and later ponder it well. Then, if you find some faults or have some doubts, you may make criticism. When you have grasped the point, you should present your understanding to your teacher. Waiting to claim immediate understanding shows that you are not really listening to the dharma.