"A mathematical theory is not to be considered complete until you have made it so clear that you can explain it to the first man whom you meet on the street"

In this quote, mathematician David Hilbert stresses the significance of clarity and simplicity in mathematical theory. He recommends that a theory can not be thought about really total up until it can be quickly understood and discussed to anybody, even someone with no anticipation of mathematics. This highlights the idea that complex concepts should be broken down and communicated in a way that is available to all, rather than being restricted to the realm of professionals. Hilbert's words also speak to the idea that true understanding of a principle originates from being able to efficiently convey it to others, rather than just mastering it oneself.