It usually takes me more than three weeks to prepare a good impromptu speech.

If one does not know to which port one is sailing, no wind is favorable.

Sometimes when you innovate, you make mistakes. It is best to admit them quickly, and get on with improving your other innovations.

I think that there is nothing, not even crime, more opposed to poetry, to philosophy, ay, to life itself than this incessant business.

The superior man understands what is right the inferior man understands what will sell.

There are no secrets to success. It is the result of preparation, hard work, and learning from failure.

In this world nothing can be said to be certain, except death and taxes.

If you cannot work with love but only with distaste, it is better that you should leave your work.

If all the economists were laid end to end, they'd never reach a conclusion.

Most of the important things in the world have been accomplished by people who have kept on trying when there seemed to be no hope at all.