I received my certificate in Teaching English as a Second Language (TESOL) in the mail a day or two ago.
I had to complete a number of hours of practice teaching. The first two lessons were a predictable disaster. In the first lesson the assessor had to step in. At that stage I wondered whether it really were possible, and thought about quitting.
However, I continued and did not act on my negative, self-defeating thoughts. By the third lesson I got some positive scores, and very nearly passed the whole thing on the fourth lesson alone. Improvement continued, although the two assessors made the same points but assigned a different weight to them. Unfortunately the one who gave greater weight to presentation assessed two-thirds of them.
By the time of the last lesson I had acquired some self-endorsement. Unfortunately the institution did not schedule any further practice lessons. After some stone-walling, discretion was used to pass me on the fourth lesson, in which I had almost passed everything in one go.
That I did not find completely satisfactory, so I did two lessons (four hours) in place of someone who could not make their scheduled practice lesson. They were not formally assessed, so they were completely solo. That has added to my feeling of self-endorsement.
So, not done in a completely standard way. It took a long time because of all the delays. Nevertheless, by not acting on my negative, self-defeating thoughts, I validated that part of Cognitive Behavioural Therapy (CBT) about challenging thoughts, and sticking with things so that anxiety reduces over time. Also, I did not act on my feeling of doom after the first lesson and create a self-fulfilling prophecy. That is another aspect of CBT - you do not know until you try. Then you can decide whether it really was so bad after all. What feels true is not necessarily true if put to the test.
So this experience validates the part of CBT about challenging thoughts and putting things to the test.
This shows that your reach can exceed your grasp.