What if happiness is contained inside a Pythagorean cup? Overflowing happiness would then simply drain away and empty the cup completely. This is why it is important to listen to Mr. Micawber’s advice and live within our means.
Similarly, if we apply the same concept to knowledge, it would be difficult to learn if one were to be satisfied with a certain level of knowledge or overestimate themselves. According to the Dunning-Kruger effect relatively unskilled persons suffer from an illusory superiority as a result of a meta-cognitive inability to recognize their own ineptitude and evaluate their ability accordingly instead of letting ideas/perceptions stagnate.