This makes changing teaching while teaching extremely difficult. The lesson already absorbs the teacher: change diverts their attention, causing mistakes elsewhere. Teachers are swept along by existing habits, even when they mean to change. Lessons rarely allow space and time to teach effectively and to change teaching at the same time. 

I like to joke, without students I’d have the time to plan such amazing learning, to maintain a tidy desk and classroom, to further my own education. The potential!

Effective training simplifies reality – Improving Teaching