Self Doubt is quite different than Great Doubt. Self Doubt is more like, "I am no good, what am I doing? "I should be able to do this better." It’s centered on “I”. This "I" is a construct. The fundamental concept of suffering is that attachment to "I". With this self image, this concept and idea of what I think I should be, we get disappointed and lose our way.
Great Doubt is “What is it?” So when we feel disappointment, we can hold it with a question, “What is it?” Then we look and pay attention to our experience. Pay attention to what is happening in the moment. Then we can see clearly, hear clearly, taste clearly, and think clearly. We are not lost in that commentary.
By Zen Master Bon Soeng