We may feel that we are not smart enough to do what we do. One explanation for this is the Dunning-Kruger effect: when you are incompetent, you can't know you're incompetent and can't properly assess your own competence.

Research shows that incompetent students think they are much better than they are and top students underestimate themselves.

Knowledge structures. The more knowledge you learn, the more subtle patterns appear. Consider learning English. The word "good" may be sufficient until you know words like "fine", "excellent", "stupendous", sublime."

Social comparisons. When you start, you...