Learning and Teaching is not easy - I've always known this. Sometimes it is easy to explain a concept or how something works, but other times it is not so easy. Some of the modules I teach I have been doing so for a few years, which means I have a lot of experience - but no guarantee that everyone in the classroom will understand what I am saying. In fact, I would be astonished if I ever had a class where 100% of the students understood 100% of the material. A topic that is easy for one student to learn may not be so for another - any teacher/lecturer will accept this. Recently I failed to explain a concept in one of my classes so that a student asked me many questions - it was not working for him. I tried my best, but in this instance I could not get him to understand what I was saying - it brought to mind a quote from Albert Einstein:
Note to self: Work harder.