Believing in Movies
If you believe what you see in martial art movies, you are an idiot. The techniques used in movies are for entertainment. They are not meant to be realistic, reliable, or effective; they are merely techniques that look good on the screen. The actors may be skilled athletes or even skilled martial artists, but the action is not real; it is choreographed movements, similar to a dance or a pattern. Do not try any of these techniques on the street, it will get you killed, and, unless you plan of being an actor, do not practice the techniques in class; you will just be wasting valuable time.
Trust will get you killed. If you trust your martial art style always to work when you need it, if you trust that everything your instructor tells you is true, or if you trust the bad guy when he says he will not hurt you if you do what he says, it will get you killed. Put your trust in logic, empirical science, and proven techniques and methods, they will not fail you.
Believing in Magic
Martial art stunts, fantastic breaking demonstrations, knockouts without touching, fantastic feats of strength by ordinary looking people, etc. fall under the auspices of magic. Magicians do not believe in magic, they are experts in making you believe in magic. Magic is entertainment, if you believe it, you are an idiot and it will get you killed.
Believing You Can Be a Great Athlete
Everyone knows one of the great athletes. He or she may be the best fighter in a school, the one who always seems to win tournaments, or the one who can effortlessly performs the most difficult techniques. These are the super athletes, the one-in-a-million. They have all the genes and innate ability to be the best at any athletic endeavor. If you believe you can attain their level of expertise or ability and that is what you concentrate upon, you are wasting your time. You can try to be the best you can be and to work around your limitations and you may become effective in self-defense situations. However, if you are constantly trying to be as good as the great athletes, you will never achieve be all you can be and when the chips are down, it can get your killed.
Zwiers, G. (2006). Martial Arts Secrets Exposed . [Online]. Available: http://www.warriorcrafts.com/martialartarticles