An expert is a man who has made all the mistakes which can be made, in a narrow field.
In the great drama of existence we are audience and actors at the same time.
Every sentence I utter must be understood not as an affirmation, but as a question.
If you think you understand it, that only shows that you don't know the first thing about it.
Prediction is difficult, especially the future.
One must always do what one really cannot.