As instructors we have a responsibility to present our students with concepts and techniques that are functional, relevant, and, most importantly, in the proper context. We should constantly evaluate the material we teach and adjust as necessary. Any system/style that fails to review its teachings on a regular basis runs the risk of becoming irrelevant, nonfunctional, and out of context. At NOVA Self Defense we have found ourselves reviewing drills and concepts after every class or seminar and discussing ways to modify them for a specific audience or improve their effectiveness.
Never let your ego or tradition prevent you from obtaining new knowledge. Cross-training is not just a way of getting a better workout. I recently read Bruce Clayton's book Shotokan's Secret. In the book he says "We must climb other mountains in order to see our own." To me this reflects the idea that training other styles / systems / sports / etc. will enhance your understanding of your primary training and provide new concepts with which to improve that training. He goes on to debunk several other myths or misperceptions about karate, including the idea that karate is empty-handed, that sparring trains you for combat, and that techniques must not be changed. (The original masters continually tweaked and changed the techniques and katas!) This book is a must read for any martial artist.
So I charge you with this. Never accept any self-defense training at face value. Always question the relevance and effectiveness of what is being presented. If something does not seem to make sense, don't assume you are just misunderstanding something. Question your instructors, look for alternative training to broaden your horizons. Climb those other mountains.