In my PGCHE class are represented a variety of different subject areas. I have noticed that some people are teaching subjects where they will be the first person ever to teach that subject to that student. A tertiary education mathematics teacher will not have this experience. All my students have done some mathematics before and they all have preconceptions about it.
I am reminded of my first driving lesson. My instructor asked if I had driven before. I said I had not. He said this was good; that a number of his students had already done some driving with a parent and his first job was to wade through the preconceptions and bad habits already formed to get back to a clean slate.
I am not saying I would like to teach addition to 18 year olds! But it is interesting to wonder about how this affects my teaching: I am always building on a body of knowledge.
