All truly wise thoughts have been thoughts already thousands of times; but to make them truly ours, we must think them over again honestly, till they take root in our personal experience.

Johann Wolfgang von Goethe

In our sleep, pain which cannot forget falls drop by drop upon the heart until, in our own despair, against our will, comes wisdom through the awful grace of God.

Aeschylus

One swallow does not make a summer, neither does one fine day; similarly one day or brief time of happiness does not make a person entirely happy.

Aristotle

The important thing is not to stop questioning. Curiosity has its own reason for existing. One cannot help but be in awe when he contemplates the mysteries of eternity, of life, of the marvelous structure of reality. It is enough if one tries merely to comprehend a little of this mystery every day. Never lose a holy curiosity.

Albert Einstein

Reading, after a certain age, diverts the mind too much from its creative pursuits. Any man who reads too much and uses his own brain too little falls into lazy habits of thinking.

Albert Einstein