We’d all agree that to teach a subject, you must know the subject. So you’d think that experts would be the best teachers, but they’re not…
In order to teach efficiently, experts try to cut right to the chase. They teach the Abstract Model. Why? Because, they’re trying to save you all the hassle of learning it, “The Hard Way”.
The problem is, as seen by our made up model, without Concrete experiences and many of them, it’s very difficult to understand the model.
Source: Why Experts Make Bad Teachers