We have self image about ourself. We expect what is happening to us should be within acceptable range of our self image. We can not accept if something happening breaching our self image.
A person studying good at school and college, started to believe about himeself as a good performing guy. He can not accept, if he is given low rating in his job. Poor feedback in job is breaching his self image as good performing guy.
We develop a belief system about ourself by seeing our face. If anything happening to me beyond my belief system, I can not tolerate.
I have a belief or opinion that I am a good programmer. I understand business models and implement them as softwares. Sometimes if I can not understand a business model and not able to implement as softwares, I can not tolerate, I will start to doubt my skills. My confidence dilutes.
The fact is nobody knows everything. There are things which we can not do. Not everything we can accompolish. When the task is within our command, we get it done, and develop confidence. When the task is beyond our comand, we are not able to do it, and loose confidence. We afraid what will happen bad because of the failure.
Failures, not able to uderstand, not able to complete a task all are part of life. If our self-image allows failures too, then we will be comfortable in embarassing moments too. We are not special, not to be scolded, criticized, embarassed. As long as our self image is flexible, we will be in a bliss.