from a students pespective... i hate the more advance students that think anyone else in a lower level is not worthy of there presence. We had this one guy that wouldn't even look at you if you weren't in the advance (MMA) class. He had a tournoment coming up and the instructor wanted everyone to give him motivation and encouragement in the days before the fight. He didn't get much. The instructor pulled a couple of us aside and asked why we were not very supportive of our team mate. We told him what the guy was like and I think he got a talking to. The former a-hole is now one of the greatest guys to have on your team, he stays around and helps some of the begginers after class, and explains any of the techniques that you may not understand. HE has become a good friend and training partner now.
Practice doesn't make perfect, practice makes permanent. Perfect practice makes perfect.