Guro Dan Inosanto has shared this idea with me many times in the past and it still holds true today. The idea of the Learning Triangle is this:  Imagine a triangle laying on its side, the base line of the triangle is to your left and the tip is to your right.  Imagine again that you are represented on the tip of the triangle and on the base line there are three points, the top corner, the bottom corner and the middle of the baseline.

The top of corner of the baseline is your teacher, he is the common source of knowledge in the given area you are studying.  The bottom corner of the baseline is your younger brother or sister in class, some one who may be new to class or the area of study.  The middle of the base line is someone who has studied for the same amount of time that you have, someone that would be considered your equal in class.

The reason for the triangle arrangement is this:  You can learn from any point on the Learning Triangle.  Obviously you learn from your teacher, but you should also be aware that you will learn from your classmates that have been training for the same amount of time as you.  They may have a slightly different point of view of the same problem and this point of view may help you learn the topic better. Then there is your younger classmate, who, through questions, may force you to look at a topic from different angles.   Having to formulate an explanation will sometimes bring you to seeking out new ways to present the material  you have learned, helping you (and the younger classmate) to learn it better.
 
Looking at learning this way . . . . . it will expand your learning and training experience.