Smart people are clever but clever doesn't mean smart.

Have you ever heard of the Dunning-Kruger effect ? If you don't know the term, you definitely have experienced the principle. This psychological rule states that it's the most incompetent who are the most confident, while the most intelligent doubt their own abilities. Why? In short, dumb people are too dumb to understand exactly how dumb they are. Smart people are clever enough to know how much they don't know.