“If you think that you are smart, you are dumb. If you think that you are dumb, you are smart.”
When I was around 14 years old, this was a phrase that I always used to say in my friendship group in high school. Being 20 now (I’m slightly older albeit with questionable maturity), I think this phrase is awfully blunt. Nonetheless, I think there is some insight to be gained by this phrase.