You can try this for yourself, either in any teaching you do, or any learning. Often we will get blocked at a particular stage in our learning. A normal response is to try harder, and to focus more on what we're doing right, and what we're doing wrong. Sometimes this helps, but sometimes it just digs us further into our rut. The way out of the rut is to re-focus on experiencing again."
See also Tom's essay on the always-additive nature of learning at School of Everything: "Once you have learnt something you see the world differently. Not only can you appreciate or do something that you couldn't appreciate or do before, but the way you saw the world before is now lost to you. This works for the small things as well as the big picture. If you learn the meaning of a new word, you won't be able to ignore it like you did previously. If you learn how to make a cup of out of clay you won't ever be able to see cups like you used to before."