Starting at the bottom, in any field,can be cause for frustration, when you feel like you´re not getting anywhere for quite some time. Those who want instant learning results will either give up, or cut corners. Then there are those who´s curve, no matter how hard they study, will take a wrong turn, because of how or with whom they are learning.
If a teacher is bored, has become staid about their subject matter, or has only been dealing with a certain aspect of their subject for some time, they may very well omit important information. not demand quality work from their students and only give half-truths or facts, in fact, the learning becomes like Chinese whispers. Inaccurately transmitted gossip, or in this case information. The learning matter may well be incorrectly explained or demonstrated, and as the student mimics the teacher, a person who has yet to perfect their chosen subject, their interpretation will be even more discrepant. Thus, as the topic is passed down the line, the knowledge becomes weaker and more erroneous.
If the teacher has become dulled by their topic, the likelihood of them having kept up-to-date with innovations in their field will be very slim. Therefore their students will also be very much behind the times, along with the poor initial education they have received from this teacher they will not benefit from the new discoveries that are out there.
So when you want to learn something, or are in need of a knowledgeable service, be sure to find a teacher or professional who is excited and passionate about their subject. Someone who knows the learning never stops and has never stopped discovering for themselves.