Change means going from the known to the unknown, taking on new beliefs or modifying old ones. Sometimes it is forced upon us - a new syllabus is introduced, we are given different classes to teach., etc. Questioning our own teaching principles and practices obviously scores high in terms of activities which involve risk. It's often difficult to accept that what we've been doing for years need not necessarily be the best way and we might have to rethink such established ideas. These are ideas which seem to have worked for us in the past and we see no reason why they should not in the future.
Most people like to think that they have an open mind.
These types of questions are often indicators of resistance to change. New ideas meet with almost immediate dismissal. This is something akin to what Dr. Edward de Bono calls 'the intelligence trap'. The first reaction to a given situation is presumed right, and from there we use our intelligence to back up our initial argument rather than to explore its possibilities. We are not likely to come up with a completely new alternative to the learning process.