Heraclitus on wisdom

You cannot step twice into the same river.

He who does not expect will not find out the unexpected, for it is trackless and unexplored.

This universe, which is the same for all, has not been made by any god or man, but it always has been, is, and will be an ever-living fire, kindling itself by regular measures and going out by regular measures.

The only true wisdom is in knowing you know nothing.

Socrates470–399 BC

By three methods we may learn wisdom: First, by reflection, which is noblest; Second, by imitation, which is easiest; and third by experience, which is the bitterest.

Confucius551–479 BC

True wisdom comes to each of us when we realize how little we
understand about life, ourselves, and the world around us.