Quotes from Stanislaw Ulam

He [John von Neumann] had the invaluable faculty of being able to take the most difficult problem and separate it into its components, whereupon everything looked brlliantly simple.

It is most important in creative science not to give up. If you are an optimist you will be willing to "try" more than if you are a pessimist.

Do not lose your faith. A mighty fortress is our mathematics. Mathematics will rise to the challenge, as it always has.