Over the course of one's life, one can experience many teachers. Some are more effective than others. Indeed, a vast knowledge of the subject and/or a glib tongue do not a great instructor make.
If one is fortunately enough to encounter a teacher that genuinely enjoys instruction, carries a deep understanding and passion for the material, takes the time to meet the student at their points of strength AND encourages them to DRAW from their weaknesses, then life-long lessons can be gained. Dwight Diller is one such teacher.
Genius manifests many ways. Sometimes, it is accompanied by challenges. In such a case, only the most dedicated and passionate - those that love deeply - can preserve. Again, Dwight is such a genius.